Ukraine's military says it is working to evacuate all remaining troops from their last stronghold in the besieged port of Mariupol, ceding control of the city to Russia after months of bombardment.
The evacuation of hundreds of Ukrainian fighters, many wounded, to Russian-held towns, likely marks the end of the longest and bloodiest battle of the Ukraine war and a significant defeat for Ukraine.
Mariupol is now in ruins after a Russian siege that Ukraine says killed tens of thousands of people in the city.
With the rest of Mariupol firmly in Russian hands, hundreds of Ukrainian troops and civilians had holed up beneath the city's Azovstal steelworks.
Civilians inside were evacuated in recent weeks, and more than 260 troops, some of them wounded, left the plant for Russian-controlled areas late on Monday.
'Heros of our time'
"The 'Mariupol' garrison has fulfilled its combat mission," the General Staff of Ukraine's Armed Forces said in a statement.
"The supreme military command ordered the commanders of the units stationed at Azovstal to save the lives of the personnel ... Defenders of Mariupol are the heroes of our time," it added.
Ukrainian Deputy Defence Minister Anna Malyar said 53 injured troops from the steelworks were taken to a hospital in the Russian-controlled town of Novoazovsk, some 32 km to the east, while another 211 people were taken to the town of Olenivka, in an area controlled by Russian-backed separatists.
- Ukrainian forces prepare for major Russian offensive push in Donbas
- Sweden and Finland move nearer NATO membership
All of the evacuees will be subject to a potential prisoner exchange with Russia, she added.
About 600 troops were believed to have been inside the steel plant. Ukraine's military said efforts were under way to evacuate those still inside.
"We hope that we will be able to save the lives of our guys," Ukrainian President Volodymyr Zelensky said in an early morning address. "There are severely wounded ones among them. They're receiving care. Ukraine needs Ukrainian heroes alive."
Five buses carrying troops from Azovstal reportedly arrive in Novoazovsk late on Monday. In one, marked with Z like many Russian military vehicles in Ukraine, men were stacked on stretchers on three levels.
One man was wheeled out, his head tightly wrapped in thick bandages.
Ukraine troops make advances around Kharkiv
Meanwhile, a Ukrainian counter-attack in recent days has reportedly driven Russian forces out of the area near Kharkiv, the biggest city in the east.
Ukraine's general staff said Russian forces were reinforcing and preparing to renew their offensive near Slovyansk and Drobysheve, southeast of the strategic town of Izyum, having suffered losses elsewhere.
Areas around Kyiv and the western city of Lviv, near the Polish border, have continued to come under Russian attack.
A series of explosions struck Lviv early on Tuesday, but there were no immediate reports of casualties or damage.
On Monday, Ukraine's defence ministry said troops had advanced all the way to the Russian border, about 40 km north of Kharkiv.
The successes near Kharkiv could let Ukraine attack supply lines for Russia's main offensive, grinding on further south in the Donbas region, where Moscow has been launching mass assaults for over a month.
Putin tones down rhetoric over NATO membership bids
Russian President Vladimir Putin appeared on Monday to climb down from threats to retaliate against Sweden and Finland for announcing plans to join the U.S.-led NATO military alliance.
"As far as expansion goes, including new members Finland and Sweden, Russia has no problems with these states - none.
"And so in this sense there is no immediate threat to Russia from an expansion to include these countries," Putin said.
The comments appeared to mark a major shift in rhetoric, after years of casting NATO enlargement as a direct threat to Russia's security, including citing it as a justification for the invasion of Ukraine itself.
Putin said NATO enlargement was being used by the United States in an "aggressive" way to aggravate an already difficult global security situation, and that Russia would respond if the alliance moved weapons or troops forward.
"The expansion of military infrastructure into this territory would certainly provoke our response," Putin said.
Finland and Sweden, both non-aligned throughout the Cold War, say they now want the protection offered by NATO's treaty, under which an attack on any member is an attack on all.
Finland and Sweden's plans, however, hit a snag when NATO member Turkey's president said he would not approve either bid.