This is CNBC's live blog tracking developments on the war in Ukraine. See below for the latest updates.
Notorious Russian private military contractor Wagner Group has been assigned responsibility for specific sectors on the front line in Ukraine, according to Britain's Defense Ministry.
"Wagner's role has probably changed because the Russian MoD has a major shortage of combat infantry," the ministry said in a tweet.
Meanwhile, Ukraine has denied Russian claims that it carried out a missile strike on a prisoner camp in Russian-controlled Donetsk.
The White House hinted that it is preparing another military aid package for Ukraine.
"I fully expect that and I think you're going to see another one relatively soon. I'm a little hesitant to stamp the date on the calendar but I think you can expect to see another announcement on the security assistance support very soon," National Security Council spokesman John Kirby told reporters.
"I don't want to preview what's in the package just yet," he said. "But I do think that in general terms, you can expect to see things in line with the kinds of security assistance you've seen in the past."
The upcoming package, the 17th such installment, would bring U.S. commitment to Ukraine to more than $8 billion since the war started in late February.
— Amanda Macias
U.S. Secretary of State Antony Blinken said he had a "frank and direct" conversation with Russian Foreign Minister Sergey Lavrov.
The call, the first since Russia invaded Ukraine in late February, follows a U.S. proposal to free detained WNBA star Brittney Griner and former Marine Paul Whelan.
"I pressed the Kremlin to accept the substantial proposal that we put forth on the release of Paul Whelan and Brittney Griner. I also emphasize that the world expects Russia to fulfill its commitments under the deal that was reached with Ukraine, Turkey and the United Nations on grain shipments from Ukraine," Blinken said alongside Secretary of Commerce Gina Raimondo.
Blinken also said that he warned Lavrov of additional sanctions should Russia annex more of Ukraine.
"Those plans would never be accepted. The world will not recognize annexations. We will impose additional significant costs on Russia if it moves forward with its plans," Blinken said.
— Amanda Macias
The U.S. Ambassador to the United Nations slammed Russia's war in Ukraine as the conflict heads into its sixth month.
"Russia has effectively set the U.N. Charter on fire," U.S. Ambassador Linda Thomas-Greenfield told the international forum's Security Council.
"Since Russia's full-scale invasion of Ukraine in February, the world has witnessed Russia's flagrant violations of international law and complete disregard for the U.N. Charter and the principles of peace," she added.
Thomas-Greenfield said that there are substantial reports of Russian forces committing human rights abuses, including the forced transfers of people to Russian territory.
She also said U.S. intelligence indicates that Russia is taking steps to annex large parts of Ukraine.
"This is galling. The acquisition of territory by force is about as clear a violation of the U.N. Charter as you can get," she added.
"We cannot, we will not stand by and let it happen," Thomas-Greenfield said.
— Amanda Macias
Russian Foreign Minister Sergey Lavrov said Moscow would soon propose a date for a call with U.S. Secretary of State Antony Blinken, their first discussion since Russia invaded Ukraine.
On Wednesday, Blinken said he will discuss the U.S. proposal to free detained WNBA star Brittney Griner and former Marine Paul Whelan with Lavrov "in the coming days."
Later on Wednesday, the Kremlin said it has not yet received a request for a phone call between Lavrov and Blinken.
— Amanda Macias
Russia's use of explosive weapons with a wide impact area has taken a heavy toll on Ukraine's health sector, a top United Nations official said.
"As of 25 July, there have been 414 attacks on health care in Ukraine, resulting in 85 deaths and 100 injuries," Under-Secretary-General for Political Affairs Rosemary DiCarlo said before the United Nations Security Council.
Access to health services, including sexual and reproductive health for women, and access to affordable child health care have also deteriorated, she said.
"The impact of the war globally is glaringly clear, consequences will only become more pronounced the longer conflict lasts particularly with the onset of winter," DiCarlo added.
— Amanda Macias
Ukraine President Volodymyr Zelenskyy said Friday that his country is ready to ship grain exports from the Black Sea ports in the south.
Earlier this month, Russia and Ukraine signed a U.N.-backed deal to resume exports of Ukrainian grain. Millions of tons of wheat have been stuck in the war-torn nation. Grain exporters in Ukrainian port cities like Odesa have been unable to ship their goods due to the conflict, fueling a global shortage of the commodity and pushing up food prices.
"Our side is fully prepared. We sent all the signals to our partners — the U.N. and Turkey, and our military guarantees the security situation," Zelenskyy reportedly said Friday.
"The infrastructure minister is in direct contact with the Turkish side and the U.N. We are waiting for a signal from them that we can start."
—Matt Clinch
Russia's Ministry of Defense claimed Friday that 40 Ukrainian prisoners of war were killed and 75 wounded in a strike on a detention center in the town of Olenivka, in Russian-controlled Donetsk.
NBC News was not able to immediately verify the Russian claim.
Ukraine officials have denied the claim, saying they did not carry out the missile strike. The officials said that Russia is trying to cover up the "torture and murder" of Ukrainian prisoners.
"The armed forces of the Russian Federation carried out targeted artillery shelling of a correctional institution in the settlement of Olenivka, Donetsk oblast, where Ukrainian prisoners were also held," the general staff of the Ukrainian Armed Forces said in a statement.
Russia has repeatedly denied carrying out war crimes.
—Matt Clinch
For the first time in weeks, Russian forces launched a missile attack on the Kyiv area on Thursday as Ukrainian troops concentrate on the south of the country.
Ukrainian officials said that Russia had attacked the northern Chernihiv region as well, to the northeast of Kyiv and close to the Belarus border.
Kyiv regional Governor Oleksiy Kuleba said on Telegram, according to Reuters, that 15 people had been injured with missiles hitting military installations in the Vyshhorod district, on the outskirts of Kyiv.
— Matt Clinch
Notorious Russian private military contractor Wagner Group has been assigned responsibility for specific sectors on the front line in Ukraine, according to Britain's Defense Ministry.
"This is a significant change from the previous employment of the group since 2015, when it typically undertook missions distinct from overt, large-scale regular Russian military activity," the ministry said in a tweet.
"Wagner's role has probably changed because the Russian MoD has a major shortage of combat infantry."
Wagner Group has long been implicated in conflicts in unstable countries around the world including Mali, Libya, Syria, Mozambique and the Central African Republic. Human rights groups accuse its mercenaries of perpetrating civilian massacres and other human rights abuses. The Kremlin has repeatedly denied any connection to Wagner.
Although its structure and even existence is disputed, Wagner is believed to have first emerged during Russia's illegal annexation of Crimea in 2014. The name has since become a catch-all term for an opaque and expansive network of businesses and entities.
— Elliot Smith and Matt Clinch
Large data leaks performed in the name of the hacktivist group Anonymous are exposing Russia's cybersecurity defenses to be weaker than previously thought, say cybersecurity specialists.
Though Russia remains strong in its offensive capabilities, data leaks of the Central Bank of Russia, the space agency Roscosmos, several of Russia's largest oil and gas companies and other Russian companies, have "disappointed" the cyber community, said Shmuel Gihon, a security researcher at the threat intelligence company Cyberint.
"We expected to see more strength from the Russian government," said Gihon, "at least when it comes to their strategic assets, such as banks and TV channels, and especially the government entities."
Anonymous has claimed responsibility for hacking more than 2,500 Russian and Belarusian sites, said Jeremiah Fowler, co-founder of the cybersecurity company Security Discovery.
The data leaked online is so large it will take years to review, he said.
The decentralized collective of hackers has pulled the veil off Russia's cybersecurity practices, said Fowler, which is "both embarrassing and demoralizing for the Kremlin."
— Monica Pitrelli
The White House declined to give an update on talks with Russia on a U.S. offer for the immediate release of WNBA star Brittney Griner and former Marine Paul Whelan.
"I really cannot go into more detail just for the privacy and safety of the process. We are sharing that we did put a substantial offer on the table," White House press secretary Karine Jean-Pierre said during a daily news briefing.
Earlier in the day, the Kremlin said that so far "there are no agreements" on a U.S. request to release Griner and Whelan from Russian custody.
The Kremlin said that Russian Foreign Minister Sergey Lavrov will address a phone call request by U.S. Secretary of State Antony Blinken when he has the time, according to a report by Interfax.
— Amanda Macias
The U.N.'s World Food Program estimates that up to 47 million more people could face acute food insecurity this year if Russia's war in Ukraine continues.
Last week, representatives from the U.N., Turkey, Russia and Ukraine signed an agreement to reopen three Ukrainian ports, an apparent breakthrough as the Kremlin's war on its ex-Soviet neighbor marches into its fifth month.
The deal follows a months-long blockade of dozens of Ukrainian ports sprinkled along the Sea of Azov and the Black Sea.
Less than 24 hours after the deal was signed though, Russian missiles rained down on Odesa, Ukraine's largest port.
The United Nations Secretary-General has previously warned that the armed conflict in Ukraine is threatening to unleash "an unprecedented wave of hunger and destitution, leaving social and economic chaos in its wake."
— Amanda Macias
