This has been CNBC's live blog covering updates on the war in Ukraine. [Follow the latest updates here.]

European Union leaders agreed to a sixth sanctions package that would immediately hit 75% of Russian oil imports, European Council President Charles Michel said, adding that embargo would expand to encompass 90% of imports by year end.

Turkish President Recep Tayyip Erdogan told Russia's Vladimir Putin he is ready to meet with officials from Russia, Ukraine, and the United Nations in Istanbul to help bring about an end to the war, the Turkish government said.

Meanwhile, Russian forces continue to pound Ukrainian positions in the country's Donbas, which Moscow has described as an "unconditional priority."

A French journalist was killed by Russian artillery in the Donbas area, a local official said.

And Russia has likely suffered "devastating losses" among its officers, the U.K.'s Ministry of Defence said in a daily intelligence update, while fears of a global food crisis mount as Ukraine's vital grain exports are stuck behind blockaded ports.

Zelenskyy says 32 media workers have been killed in the war

Ukrainian President Volodymyr Zelenskyy says 32 media workers have been killed since Russia invaded Ukraine on Feb. 24.

Among them is Frédéric Leclerc-Imhoff, a French journalist with the TV channel BFM TV, who suffered a fatal neck wound while riding in an armored evacuation vehicle that was shelled by Russian forces, Sky News reported.

"A little over a month ago, I gave an interview to this particular TV channel," Zelenskyy said in his nightly address. "This was my first interview with the French media during a full-scale war."

"My sincere condolences to Frédéric's colleagues and family," Zelenskyy said.

— Chelsea Ong

Oil prices rise after EU agrees to ban about 90% of Russian crude

Crude prices rose during Asia hours after EU leaders agreed to ban about 90% of Russian oil by the end of 2022.

The move would immediately affect 75% of Russian oil imports, says Charles Michel, president of the European Council.

The ban is part of the European Union's sixth sanctions package on Russia since it invaded Ukraine.

"The European Council agrees that the sixth package of sanctions against Russia will cover crude oil, as well as petroleum products, delivered from Russia into Member States, with a temporary exception for crude oil delivered by pipeline," according to a May 31 statement from the European Council.

That temporary exception covers the remaining Russian oil not yet banned, European Commission President Ursula Von der Leyen said in a press conference.

— Weizhen Tan

Sanctioned Russian billionaire completes the sale of the British soccer team he owned

A British soccer team owned for 19 years by a sanctioned Russian-Israeli billionaire linked to Vladimir Putin has been sold.

A consortium led by Los Angeles Dodgers co-owner Todd Boehly has purchased the Chelsea soccer team from Roman Abramovich, the billionaire who was sanctioned by the British government over his ties to Putin following Russia's invasion of Ukraine, in a £4.25 billion ($5.38 billion) deal.

Abramovich put the Chelsea team up for sale on March 2, a week after the invasion and a few days before the British government added his name to a list of sanctioned Russian oligarchs. Among other conditions, the sanctions barred the Chelsea team from signing new players or offering new contracts.

With the team now under new ownership, those restrictions will be lifted.

— John Rosevear

Russia would strike 'decision making centers' including those "not in Kyiv," if US sent long-range rocket systems to Ukraine

A senior Russian security official said that U.S. President Joe Biden's decision not to send Ukraine missiles capable of striking Russia is a "reasonable" one and that Russia would counterattack if its cities were hit.

In a post to his Telegram channel, the deputy head of Russia's Security Council Dmitry Medvedev said if Russian cities were attacked, the country's armed forces would have struck back at "criminal decision making centers."

"And some of them are located not in Kyiv at all," Medvedev wrote. "There's no need to explain what's next."

— John Rosevear

Turkish president Erdogan tells Putin he is ready to help end Ukraine war

Turkish President Recep Tayyip Erdogan told Russia's Vladimir Putin in a telephone conversation on Monday that he is ready to meet with officials from Russia, Ukraine, and the United Nations in Istanbul to help bring about an end to the war, according to a statement from the Turkish government.

Erdogan told Putin that there is a "need for steps that will minimize the negative effects of the war and build trust" by ending hostilities as soon as possible, the Turkish statement said.

Russia's government confirmed that the two leaders had spoken and said that Putin told Erdogan that Russia is ready to "facilitate the unhindered sea transit of goods" in the Black and Azov Seas, including the export of grain from Ukrainian ports.

Putin added that Russia could export "significant volumes" of fertilizer and agricultural products, helping to ease concerns about the global food market, if and when Western sanctions against Russia are lifted.

— John Rosevear

Kids play at being soldiers near Kyiv

Ukrainian boys Andrii, aged 12 and his friend Valentyn 6, play at being soldiers and man their makeshift checkpoint in their village next to a school crossing. The two boys have become well known to passing motorists on May 27, 2022 in Stoyanka, Ukraine. As Russia concentrates its attack on the east and south of the country, residents of the Kyiv region are returning to assess the war's toll on their communities. The towns around the capital were heavily damaged following weeks of brutal war as Russia made its failed bid to take Kyiv.

As Russia concentrates its attack on the east and south of the country, residents of the Kyiv region are returning to assess the war's toll on their communities. The towns around the capital were heavily damaged following weeks of brutal war as Russia made its failed bid to take Kyiv.

— Getty Images

Ammonia pipeline damaged and leaking, local Ukrainian official says

Ammonia gas is leaking from a damaged pipeline in Ukraine's Donetsk region, according to the local governor.

Pavlo Kyrylenko, governor of the Donetsk region in southeastern Ukraine, said that a pipeline built to carry ammonia from Togliatti in Russia to the Ukrainian city of Odesa was damaged "as a result of hostilities" and is leaking ammonia gas.

According to Kyrylenko, winds are carrying the dangerous gas from the leak near the village of Travneve towards the city of Bakhmut. Bakhmut had a population of about 72,000 before the war began.

The Togliatti-Odesa pipeline is the longest ammonia pipeline in the world. According to the governor, the damaged section is part of a branch that has not been used since 2014.

There is currently no information on casualties, Kyrylenko said.

— John Rosevear

A French journalist was killed by Russian artillery, local Ukrainian official says

A French journalist has been killed in Ukraine, according to a regional governor.

In posts to the messaging service Telegram, Serhiy Haidai said that an "accredited" French journalist suffered a fatal neck wound while riding in an armored evacuation vehicle that was shelled by Russian forces.  

Haidai is the governor of the Luhansk region in eastern Ukraine. Luhansk is part of the Donbas area that Russian forces are attempting to occupy and control.

According to Haidai, the vehicle was on its way to pick up people as part of a local evacuation when it came under fire. He said that the evacuation effort has been stopped for now.

French president Emmanuel Macron confirmed the death of the journalist, Frédéric Leclerc-Imhoff, in a tweet.

Update: The French 24-hour news channel BFMTV has released a statement on Leclerc-Imhoff's death.

32-year-old Frédéric Leclerc-Imhoff had worked for our channel for six years. He was a graduate of the Institute of Journalism Bordeaux Aquitaine. It was his second mission to Ukraine since the start of the Russian invasion, which began on February 24.

The Altice media group and the editorial staff of BFMTV share the pain of his family and loved ones. This tragic event reminds us of the dangers faced by all journalists who have been reporting this conflict at the risk of their lives for more than three months now.

— John Rosevear

Ukrainian volunteers mark the 500th camouflage net in Odesa

People weave camouflage nets in Odesa, Ukraine. Ukrainian volunteers mark the 500th net which they made for the Ukrainian army.

— Getty Images

EU should reach 'overall' agreement on Russian oil ban today: Bulgarian PM

After much negotiation, the EU should be able to reach an "overall" agreement on an embargo of Russian oil imports on Monday before the EU leaders' summit begins, Bulgarian Prime Minister Kiril Petkov said.

"I think it will pass with certain derogations," Petkov was quoted by Reuters as saying.

"Overall it should pass, depending on some individual characteristics and criteria that member states may have," he said.

Support for ending Russian energy imports has grown within the bloc since Russia launched its invasion of Ukraine, but with significant opposition and delay as many EU states rely heavily on Russia for their energy needs. As a whole, the bloc imports just over one-third of its oil from Russia.

Hungary has been the main roadblock in enacting a Russian oil ban and is set to get an exemption along with a few other landlocked states that receive their oil via pipeline. To accommodate these countries, the EU's ban will target only Russian oil brought in by tankers. This sanctions package would be the sixth from the EU since the war began in late February.

— Natasha Turak

Some 90% of all buildings in Severodonetsk are damaged, Zelenskyy says

Russian shelling has damaged the vast majority of buildings in the eastern city of Severodonetsk, Ukrainian President Volodymyr Zelenskyy said.

"Some 90% of buildings are damaged. More than two-thirds of the city's housing stock has been completely destroyed. There is no telecommunication," Zelenskyy said in his nightly address. Other Ukrainian officials have described fierce fighting in the area.

Russian forces are surrounding Severodonetsk, a city in the Luhansk Oblast which many fear could be the next Mariupol. It had a pre-war population of some 100,000 people, now reduced to roughly 10,000, authorities have said. Severodonetsk and Lysychansk are the only remaining parts of the Luhansk region in the Donbas still under Ukrainian government control.

Russian Foreign Minister Sergei Lavrov said on Sunday that for Moscow, the Donbas was an "unconditional priority."

— Natasha Turak

Germany to relax its visa rules in support of Russian dissidents fleeing to the country

Germany is set to remove some of the red tape surrounding visas for Russians, specifically those in danger in Russia for being critical of Vladimir Putin's government and the war in Ukraine, the country's Interior Ministry said.

"We want to offer Russian journalists who are being persecuted in Russia protection in Germany," Nancy Faeser, a spokesperson for the ministry, said. The move comes despite warnings from Germany's intelligence services that Russians working in German companies could pose espionage threats.

Those who would qualify to stay longer in Germany than the 90 days on the Schengen tourist visa include human rights activists, journalists, and NGO and civil society group employees that have taken a stand against the war, the ministry said during a government news conference. The changes follow activism by German human rights groups pushing for state support of Russian dissidents whose lives were under threat there.

— Natasha Turak

Fierce fighting, civilians killed in Severodonetsk as Russian troops enter city's outskirts

Russian troops have entered the outskirts of Severodonetsk, the eastern-most city still under Ukrainian control and a last holdout in the Luhansk region.

"Unfortunately we have disappointing news, the enemy is moving into the city," regional governor Serhiy Haidai said on Ukrainian television, describing the fighting as "very fierce."  

Haidai said in a statement earlier on Monday that two civilians had been killed and five injured by Russian shelling, and that 12 houses in the city were destroyed as well as 18 in neighboring Lysychansk.

"Russian shells killed two Severodon residents and wounded five others," Haidai wrote in a Telegram post. "Most of them are residents of one block in the old part of the city. They were preparing food in the yard when the shelling suddenly started. Two residents of Sirotyn were seriously injured. All the wounded received home care and are already in hospitals in Donetsk region."

— Natasha Turak

Ukraine's Eurovision-winning band raises $900,000 for military by auctioning trophy

The winners of the annual Eurovision song contest, Ukraine's Kalush Orchestra, raised $900,000 by auctioning off their trophy to support the Ukrainian military.

The funds from the sale of the trophy, an embellished crystal microphone, will be used to buy the PD-2 drone system, which includes three aircraft and a ground control station.

The PD-2 is made by Ukrainian unmanned aerial systems manufacturer Ukrspecsystems and has a range of more than 124 miles, according to the company. The auction was held on Facebook and hosted by Ukrainian TV presenter Serhiy Prytula.

The winning bid came from European crypto exchange WhiteBit, which made the purchase with 500 ether at a value of $900,000.

Eurovision is an international song contest that's been held annually since 1956, where countries from Europe put forward bands and songs to compete for the most votes from the public and a panel of judges. Ukraine's hip-hop and folk band Kalush Orchestra won in a landslide with their song Stefania, a powerful ode to Ukraine's mothers.

— Natasha Turak

After a failed attempt, EU to continue negotiating potential sanctions on Russian oil

The EU will continue to work Monday toward an agreement to embargo Russian oil, after attempts to do so on Sunday failed.

The talks are largely held up by Hungary, a major user of Russian oil and whose leader Viktor Orban is on friendly terms with Russia's Vladimir Putin.

Budapest over the weekend signaled support for a European Commission proposal that would apply sanctions only on Russian oil brought into the EU by tankers, which would allow landlocked energy importers Hungary, Slovakia and the Czech Republic to continue to receive their Russian oil via pipeline until alternative sources can be found. Talks were held up however by demands from Hungary for EU financing.

The proposed sanctions on oil imports would be part of the EU's sixth sanctions package on Russia since it invaded Ukraine in late February.

Roughly 36% of the EU's oil imports come from Russia. Energy prices, already high at the start of this year, have skyrocketed since Putin launched the war against Ukraine.

— Natasha Turak

UK ministry says Russian forces likely suffered 'devastating losses' among officers

The Russian army has likely suffered "devastating losses" among its mid and junior ranking officials, which will likely exacerbate problems in modernizing its approach to command and control, the U.K. defense ministry said.  

Junior officers are leading lowest level tactical actions because the army lacks highly trained and empowered non-commissioned officers who fulfil that role in Western forces, the ministry said in an intelligence update.

"More immediately, battalion tactical groups (BTGs) which are being reconstituted in Ukraine from survivors of multiple units are likely to be less effective due to a lack of junior leaders," the ministry added.

"Brigade and battalion commanders likely deploy forwards into harm's way because they are held to an uncompromising level of responsibility for their units' performance," the ministry said.

The lack of experienced and credible commanders is also likely to result in a further drop in morale and continued poor discipline following multiple credible reports of localized mutinies amongst Russian forces, the ministry added.

— Chelsea Ong

West waited too long to confront Putin and now he has all the leverage, professor says

The world, particularly the West, should have been more alert to Putin's actions in Georgia and Ukraine in previous years and should have more actively engaged with Russia then, says Angus Blair, professor at the American University in Cairo.

Ukraine's Donbas 'unconditional priority' for Moscow, Russia's Lavrov says

The "liberation" of Ukraine's Donbas is an "unconditional priority" for Moscow, while other Ukrainian territories should decide their future on their own, RIA news agency cited Russia's Foreign Minister Sergei Lavrov as saying on Sunday.

"The liberation of the Donetsk and Luhansk regions, recognized by the Russian Federation as independent states, is an unconditional priority," Lavrov said in an interview with French TV channel TF1, according to RIA.

For the rest of the territories in Ukraine, "the people should decide their future in these areas," he said.

— Reuters

EU fails to reach agreement on Russia oil embargo

The European Union failed to reach an agreement on a Russian oil embargo, a senior EU official told Reuters.

Diplomats will still try to make progress ahead of a Monday-Tuesday summit on an exemption for pipeline deliveries to landlocked Central European countries, officials told the news agency.

The proposed sanctions, which would be the EU's sixth package in response to Russia's invasion of Ukraine, are facing oil supply concerns from countries including landlocked Hungary.

Talks have been going on for a month, and would continue Monday, Reuters said.

— Leslie Josephs

Read CNBC's previous live coverage here:

Zelenskyy visits frontlines; Lithuania raises money to buy combat drone for Ukraine