The severity of the consequences of war on millions of children in Ukraine was brought to attention by both Ukrainian President Volodymyr Zelenskyy and UNICEF ambassador and British actor who is known for his role in the "Pirates of the Caribbean" franchise Orlando Bloom.

"The war is destroying the childhood of Ukrainian children," Zelenskyy shared in a video of his meeting with Bloom released on Monday. Thousands of schools were damaged or destroyed, he said.

"Almost 2.7 million Ukrainian schoolchildren are forced to learn online or in a mixed way," he said. Girls and boys were at risk of developing depression, anxiety or other mental health problems, Zelenskyy added.

Bloom, who has been a UNICEF ambassador for humanitarian projects since 2009, said at the meeting that he had visited a family with five children of their own and four adopted war orphans.

UNICEF supports such parents "so that every Ukrainian child can be part of a warm, nurturing and devoted family," said the actor. Such models are better for children than care homes, he said in comments posted on Instagram.

"Children in Ukraine need to get their childhood back," Bloom said.

He also addressed the fate of "missing children" whose whereabouts need to be clarified. Bloom, 46, called Russian President Vladimir Putin, without mentioning his name, a "war criminal."

The International Criminal Court (ICC) in The Hague, Netherlands had issued an arrest warrant for Putin for abducting children. Russia denies that children were deported. Moscow says the children were taken to safety from the war in Ukraine.

Zelenskyy said that thousands of Ukrainian girls and boys are being forcibly "Russified" and deprived of their Ukrainian identity.