The Kremlin said Putin had personally guaranteed the prisoners would be treated according to international standards and Ukrainian officials said they could be exchanged for Russian captives.
Ukrainian Deputy Prime Minister Iryna Vereshchuk said Kyiv aimed to arrange a prisoner swap for the wounded once their condition stabilised.
But Russian Deputy Ambassador to the United Nations Dmitry Polyansky said there had been no deal, tweeting: “I didn’t know English has so many ways to express a single message: the #Azovnazis have unconditionally surrendered.”
TASS news agency reported a Russian committee planned to question the soldiers, many of them members of the Azov Battalion, as part of an investigation into what Moscow calls “Ukrainian regime crimes”.
High-profile Russian politicians spoke out against any prisoner swap. Vyacheslav Volodin, speaker of the State Duma, Russia’s lower house, said: “Nazi criminals should not be exchanged.”
Duma deputy Leonid Slutsky, one of Russia’s negotiators in talks with Ukraine, called the evacuated combatants “animals in human form” and said they should be executed.
Formed in 2014 as an extreme right-wing volunteer militia to fight Russian-backed separatists, the Azov Regiment denies being fascist or neo-Nazi. Ukraine says it has been reformed and integrated into the National Guard.
Natalia, the wife of a sailor among those holed up in the plant, told Reuters she hoped “there will be an honest exchange”. But she was still worried: “What Russia is doing now is inhumane.”
The denouement of the battle for Mariupol is Russia’s biggest victory since it launched what it calls a “special military operation” in Ukraine on February 24.
It gives Moscow control of the Azov Sea coast and an unbroken stretch of eastern and southern Ukraine. But the port lies in ruins, and Ukraine believes tens of thousands of people were killed under months of Russian bombardment.
Meanwhile, Sweden and Finland have submitted their applications to join the NATO military alliance in Brussels, marking the start of a process that would fortify Europe’s defences if Russia threatens the region.
“This is a good day at a critical moment for our security,” North Atlantic Treaty Organisation Secretary General Jens Stoltenberg told reporters. “This is a historic moment which we should seize.”
The application will be assessed by all 30 NATO allies and requires unanimous agreement. Turkish President Recep Tayyip Erdogan on Monday signalled he wouldn’t allow the Nordic nations to join, alleging they support Kurdish militants that his government regards as terrorists.
Turkey is engaged in talks with Sweden and Finland, and NATO members say they’re confident the Turkish concerns can be overcome.
Finnish President Sauli Niinisto, who is travelling to Washington on Thursday with Swedish Prime Minister Magdalena Andersson, said he’s “optimistic” Turkey’s stance can be “managed through discussions.”
Struggles on eastern front
Russia’s offensive in the east, meanwhile, appeared to be making little progress, although the Kremlin says all its objectives will be reached.
Ukraine’s military command said Russia continued to shell Ukrainian positions along the entire frontline in the east on Wednesday.
“In the Kharkiv direction, the enemy focused on maintaining its positions and preventing the further advance of our troops,” Ukraine’s general staff said in a statement.
Around a third of the Donbas was held by Russia-backed separatists before the invasion. Moscow now controls around 90 per centof Luhansk region, but it has failed to make major inroads towards the key cities of Sloviansk and Kramatorsk in Donetsk to control the entire Donbas.
Ukrainian forces have advanced at their fastest pace for more than a month, driving Russian forces out of the area around Kharkiv, Ukraine’s second-largest city.
Ukraine says its forces had reached the Russian border, 40 km north of Kharkiv. They have also pushed at least as far as the Siverskiy Donets river 40 km to the east, where they could threaten Russian supply lines.
Putin may have to decide whether to send more troops and hardware to replenish his weakened invasion force as an influx of Western weapons, including scores of US and Canadian M777 howitzers that have longer range than their Russian equivalents, bolster Ukraine’s combat power, analysts said.
“Time is definitely working against the Russians … The Ukrainians are getting stronger almost every day,” said Neil Melvin of the RUSI think-tank in London.