KYIV, Ukraine -- More than 260 Ukrainian fighters, including some who are badly wounded, were evacuated Monday from a steel plant in the ruined city of Mariupol and taken to areas under Russia's control, the Ukrainian military said.
Deputy Defense Minister Anna Maliar said 53 seriously wounded fighters were taken to a hospital in Novoazovsk, east of Mariupol. An additional 211 fighters were evacuated to Olenivka through a humanitarian corridor. An exchange would be worked out for their return home, she said.
Maliar said missions are underway to rescue the remaining fighters inside the plant, the last stronghold of resistance in the ruined southern port city of Mariupol.
"Thanks to the defenders of Mariupol, Ukraine gained critically important time," she said. "And they fulfilled all their tasks. But it is impossible to unblock Azovstal by military means."
Officials also planned to keep trying to save the fighters who remained inside. Military experts generally put the number of fighters at the plant at anywhere from a few hundred to 1,000.
"The work to bring the guys home continues, and it requires delicacy and time," said President Volodymyr Zelenskyy.
The steel mill's defenders got out as Moscow suffered another diplomatic setback in its war with Ukraine, with Sweden joining Finland in deciding to seek NATO membership.
Earlier Monday, the Russian Defense Ministry announced an agreement for the wounded to leave the steelworks for treatment in a town held by pro-Moscow separatists.
After nightfall Monday, several buses pulled away from the steel mill accompanied by Russian military vehicles.
There was no immediate word on whether the wounded would be considered prisoners of war.
Russian forces pounded targets in the industrial heartland of eastern Ukraine known as the Donbas, and the death toll, already many thousands, kept climbing with the war set to enter its 12th week on Wednesday.
The eastern city of Sievierdonetsk came under heavy shelling that killed at least 10 people, said Serhiy Haidai, the governor of the Luhansk region. In the Donetsk region, Gov. Pavlo Kyrylenko said on Facebook that nine civilians were killed in shelling.
But Ukrainian troops also advanced as Russian forces pulled back from around the northeastern city of Kharkiv in recent days. Zelenskyy thanked the soldiers who reportedly pushed all the way to the Russian border in the Kharkiv region in a symbolic gain.
Video showed Ukrainian soldiers carrying a post that resembled a striped blue and yellow Ukrainian border marker. Then they placed it on the ground while a dozen of the soldiers posed next to it, including one with belts of bullets draped over a shoulder.
"I'm very grateful to you, on behalf of all Ukrainians, on my behalf and on behalf of my family," Zelenskyy said in a video message. "I'm very grateful to all the fighters like you."
The Ukrainian border service said the video showing the soldiers was from the border "in the Kharkiv region," but would not elaborate, citing security reasons. It was not immediately possible to verify the exact location.
Ukrainian border guards said they also stopped a Russian attempt to send sabotage and reconnaissance troops into the Sumy region, some 90 miles northwest of Kharkiv.
Russia has been plagued by setbacks in the war, most glaringly in its failure early on to take the capital of Kyiv. Much of the fighting has shifted to the Donbas but also has turned into a slog, with both sides fighting village-by-village.
Howitzers from the U.S. and other countries have helped Kyiv hold off or gain ground against Russia, a senior U.S. defense official said. The official, who spoke on condition of anonymity to discuss the U.S. military assessment, said Ukraine has pushed Russian forces to within a half-mile to 2.5 miles of Russia's border but could not confirm if it was all the way to the frontier.
The official said Russian long-range strikes also appeared to target a Ukrainian military training center in Yavoriv, near the Polish border. There were no immediate reports of casualties.
The international response to the Russian invasion picked up pace.
Sweden's decision to seek NATO membership came after a similar decision by neighboring Finland in a historic shift for the countries, which were nonaligned for generations.
Swedish Prime Minister Magdalena Andersson said her country would be in a "vulnerable position" during the application period and urged her fellow citizens to brace themselves.
"Russia has said that that it will take countermeasures if we join NATO," she said. "We cannot rule out that Sweden will be exposed to, for instance, disinformation and attempts to intimidate and divide us."
But President Recep Tayyip Erdogan of Turkey, a NATO member, ratcheted up his objection to their joining. He accused the countries of failing to take a "clear" stance against Kurdish militants and other groups that Ankara considers terrorists, and of imposing military sanctions on Turkey.
He said Swedish and Finnish officials who are expected in Turkey next week should not bother to come if they intend to try to persuade Turkey to drop its objection.
"How can we trust them?" Erdogan asked at a joint news conference with the visiting Algerian president.
All 30 current NATO members must agree to let the Nordic neighbors join.
Russian President Vladimir Putin said Moscow "does not have a problem" with Sweden or Finland as they apply for NATO membership, but that "the expansion of military infrastructure onto this territory will of course give rise to our reaction in response."
Putin, whose remarks came at a Kremlin summit of the Collective Security Treaty Organization -- Russia's answer to NATO, found only one of his five assembled allies supporting him on Ukraine. The alliance of six post-Soviet states, the organization was marking the 30-year anniversary of its founding.
Speaking first in the televised portion of the summit, President Alexander Lukashenko of Belarus -- who has supported Putin's war in Ukraine but has not sent troops -- criticized other members of the alliance for insufficiently backing Russia and Belarus in the face of Western sanctions.
He noted how the organization had sent forces to Kazakhstan in January to prop up the country's government in the face of protests -- yet had left Russia largely on its own amid the war in Ukraine.
"Are we just as connected by bonds of solidarity and support now?" he asked, after mentioning the alliance's support of the Kazakh government. "Maybe I'm wrong, but as recent events have shown, it seems the answer is no."
Kazakhstan has said that it would not help Russia circumvent international sanctions. In a United Nations vote March 2 condemning the invasion of Ukraine, Belarus was the only post-Soviet country to take Russia's side.
"Look at how monolithically the European Union votes and acts," Lukashenko said at Monday's summit, sitting at a round table with the other leaders. "If we are separate, we'll just be crushed and torn apart."
Leaders of the bloc's other four members -- Armenia, Kazakhstan, Kyrgyzstan and Tajikistan -- did not even mention Ukraine in their televised remarks.
Putin, speaking at the summit, again tried to justify his invasion by claiming that "neo-Nazism has long been rampant in Ukraine." But he took a more measured tone in discussing the likely accession of Sweden and Finland to NATO -- the latest evidence that Putin appears to be trying to limit, for now, an escalation of his conflict with the West.
"Russia, I would like to inform you, dear colleagues, has no problem with these states," Putin said, adding that NATO's expansion to include Sweden and Finland poses "no direct threat to us."
"But the expansion of military infrastructure to this territory will certainly cause our response," he continued. "We will look at what that will be based on the threats that are created."
Putin launched the invasion on Feb. 24 in what he said was an effort to check NATO's expansion. NATO Secretary-General Jens Stoltenberg has said the membership process for both could be quick.
In Germany, Chancellor Olaf Scholz's party said Monday it sees no need for changes to the German leader's often-criticized approach to the war in Ukraine after an election in Germany's most populous state brought a clear defeat for his center-left Social Democrats.
Germany's main opposition party, the center-right Christian Democratic Union, took 35.7% of the vote to win Sunday's election in North Rhine-Westphalia state, home to nearly 18 million people. It finished nine points ahead of Scholz's Social Democrats, despite expectations of a closer race in what was long a center-left stronghold.
A combination of local and national factors appeared to have led to the result, which came with a feeble turnout of only 55.5%. The CDU's national leader, Friedrich Merz, argued that foreign and security policy played a significant role and that was "decidedly negative" for Scholz's party.
Scholz declared in February that the Russian invasion of Ukraine marked a "turning point" and announced a big increase in military spending. The German government broke with tradition to supply arms to Ukraine, but the chancellor faced criticism from the opposition and parts of his own coalition for initially hesitating to send heavy weapons and for sometimes appearing indecisive.
However, the Social Democrats' co-leader, Lars Klingbeil, said Monday that "there is no need to change anything."
He said he saw clear support during the campaign for the policy of "delivering weapons but also weighing things up, for not turning off the gas tap overnight so as not to endanger jobs in an industrial state like North Rhine-Westphalia."
But he conceded that the party needed to do a better job of communicating what it is doing for ordinary voters.
Also Monday, McDonald's said it has started selling its business in Russia, ending a relationship that has lasted more than three decades. It cited the humanitarian crisis caused by the war, noting that staying in Russia "is no longer tenable, nor is it consistent with McDonald's values." The company was the first fast-food restaurant to open in the Soviet Union.
Information for this article was contributed by Oleksandr Stashevskyi, Ciaran McQuillan, Yuras Karmanau, Mstyslav Chernov, Andrea Rosa, Elena Becatoros and other staff members of the Associated Press; and by Anton Troianovski of The New York Times.