Russia says it has sent 900 Ukrainian soldiers to a former prison colony in a Russia-controlled part of Donetsk.

Meanwhile, the war in Ukraine is likely to continue throughout the summer and possibly beyond, despite signs that parts of the country are returning to some normalcy, Ukraine's presidential advisor Oleksii Arestovych said, according to NBC News.

"It is quite clear to me that this war is unlikely to end by the fall," Arestovich said on Ukrainian TV, NBC News reported.

President Joe Biden, flanked by the leaders of Sweden and Finland, said both nations have the "full backing" of the United States in their bid to join NATO.

High Commissioner for Human Rights said the death toll in Ukraine is likely higher, because the armed conflict can delay reports.

The Red Cross noted that it is not transporting POWs to the places where they are held, with Russia reporting yesterday that it had transferred 900 Ukrainian fighters from the plant to a former prison colony.

Ukraine's armed forces have said the main focus of Russian fighters is on Donetsk in eastern Ukraine.

In the latest operational update posted on Facebook, Ukraine said 16 Russian attacks were repulsed in the Donetsk and Luhansk directions last night with eight Russian tanks, 17 units of armored combat vehicles, four special armored vehicles and six conventional enemy vehicles destroyed.

They also said Russian forces were trying to regain lost positions around the major city of Kharkiv in northeastern Ukraine.

One of Ukrainian President Volodymyr Zelenskyy's advisors has said that a cease-fire in Ukraine is impossible unless all Russian troops withdraw.

On Twitter Thursday, Mykhailo Podolyak said: "do not offer us a ceasefire - this is impossible without total Russian troops withdrawal.".

Ukraine is not interested in new "Minsk" accords and a renewal of the war in a few years, he said, referring to several failed agreements which aimed to end the conflict in the Donbas region of eastern Ukraine —between pro-Russian separatists and Ukrainian forces — that had been going on since 2014 before Russia's wider invasion.

"Many officials involved in the invasion of Ukraine will likely be increasingly distracted by efforts to avoid personal culpability for Russia's operational setbacks," the Ministry of Defence said.

Russia said 900 Ukrainian soldiers have been taken to a former prison colony, in a Russian-controlled part of Donetsk.

Speaking on Wednesday, Russian Foreign Ministry spokeswoman Maria Zakharova said, citing Russia's defense ministry, that 959 Ukrainian fighters, including 51 with severe wounds, "have laid down their arms over two days.".

On Monday, Ukraine's human rights ombudsman said on Telegram that the Russian military was holding more than 3,000 civilians from Mariupol at the former penal colony with some subjected to interrogation and torture, she said.

There were expectations that they could be exchanged for Russian soldiers in Ukrainian control but that's uncertain.

The complex was seen as the last stronghold of Ukraine's forces in the southern port city — one that Russia has aimed to control from the start of its invasion on Feb.

The war in Ukraine is likely to continue through the summer and possibly beyond, despite signs that some parts of the country are returning to some normalcy, Ukraine's presidential advisor Oleksii Arestovych said, NBC News cited.

"It is quite clear to me that this war is unlikely to end by the fall," Arestovich said on Ukrainian TV, according to NBC News.

"We're confident that at the end of the day, Finland and Sweden will have an effective and efficient accession process, [and] that Turkey's concerns can be addressed," said Biden's national security advisor Jake Sullivan