Russia and Ukraine exchanged over 200 prisoners of war on Tuesday, according to Ukrainian President Volodymyr Zelenskyy and Interfax, a Russian news agency.

During his daily evening address, Zelenskyy said 130 Ukrainians were "brought home from Russian captivity," including privates and sergeants from the army, navy and national guard.

"Just as we remember every corner of our country that is under occupation, we remember every single person in Russian captivity," he said.

Ninety Russians were released from the Ukrainian side back to Russia, though Russia said Ukraine originally agreed to release 160 Russians, Interfax reported.

"During the exchange of prisoners of war on Tuesday, the Ukrainian side agreed to return only 90 Russians, despite an earlier agreement on the exchange of '160 for 160,'" Tatyana Moskalkova, human rights ombudsman for the Russian Federation said, according to Interfax.

-ABC News' Ellie Kaufman

Up to 30,000 Russian soldiers have been killed or injured in Bakhmut over the last several months amid intense fighting in the eastern Ukrainian city, Western officials said in a briefing Tuesday.

The ratio of dead to injured was "unclear," said the officials, who described Ukraine’s refusal to withdraw from the city -- even though its forces are surrounded on three sides -- as "a sound tactic" given that "lots of Russians are being killed."

"What we're seeing is a horrific level of Russian casualties for minimal gains," they said, noting that an estimated 200,000 Russian soldiers have been killed or wounded overall since the war began.

In the past 24 hours, 244 Russian troops were killed and 315 wounded in Bakhmut, Serhiy Chevrevaty, a spokesman for Ukraine's eastern group of forces, said during a national telethon on Tuesday.

The officials refused to say how many Ukrainians have been killed or injured in and around Bakhmut but claimed it was "significantly lower."

They also were unable to put a clear time frame on when a Ukrainian withdrawal might come, though noted the possibility of a Ukrainian counteroffensive should not be ruled out.

-ABC News' Tom Soufi Burridge

Thirteen people have been found dead since a rocket struck an apartment building in Zhaporizhzhia, Ukraine, authorities said.

The governor there has called for a national day of mourning on Monday.

The State Emergency Situation of Ukraine in Zaporizhzhia initially posted on their Telegram account Friday that seven people were dead.

So far, 11 people have been saved, and 20 people were able to evacuate the building.

-ABC News' Ellie Kaufman

U.S. Attorney General Merrick Garland made an unannounced visit to Ukraine on Friday at the invitation of the Ukrainian prosecutor general to join Ukrainian President Volodymyr Zelenskyy and other international partners at the United for Justice Conference.

Garland attended several meetings while he was there.

-ABC News' Alexander Mallin

The Russian oligarch behind the Wagner private paramilitary group fighting for the Kremlin in Ukraine is threatening a mutiny if his forces are not resupplied with ammunition soon.

Yevgeny Prigozhin, owner and curator of the Wagner group, penned a letter to Russian Defense Minister Sergei Shoigue, demanding ammunition be provided to his forces on the battlefield.

In the letter, Prigozhin wrote that if supply problems are not fixed fast, he will complain to Russian President Vladimir Putin and his mercenaries would abandon their positions in Bakhmut, Ukraine, where heavy fighting has been going on for weeks, The Moscow Times reported.

“I appeal to Shoigu with a request to immediately issue ammunition. In case of refusal, I consider it necessary to convey to the Supreme Commander-in-Chief information about the existing problem in order to make a decision and about the advisability of further presence of Wagner PMC in Bakhmut in the conditions of a shortage of ammunition," Prigozhin wrote.

He added, "If the deficit is not replenished ... we will be forced to withdraw part of the units from this territory, and then everything else will crumble. Therefore, the bell is already ringing -- it is called an alarm."

Emphasizing the urgency, Prigozhin noted that Ukraine is planning to launch a counteroffensive soon.

There was no immediate public response from Shoigu or the Kremlin.

"We need to stop deceiving the population and telling that everything is fine with us," Prigozhin wrote. "I must honestly say: Russia is on the brink of disaster. If these screws are not adjusted today, the 'aircraft' will crumble in the air."