STORY: It was his first trip to Ukraine since 2016, the British actor said. He also met with Ukraine's President Volodymyr Zelenskiy.

"I would have never expected the war to have escalated throughout the country since I was there," Bloom said on Instagram.

"But today, I was fortunate to hear children's laughter at a UNICEF-supported Spilno center, a safe, warm, and nurturing space for children to play, learn and receive psychosocial support."

The Spilno centers, spread throughout Ukraine, offer support for displaced children and their families, with more than half a million children and their caregivers having visited one in the past year, according to a UNICEF statement on its website.

As of March 26, at least 465 children have been killed in the 13-month-long war Russia waged against its neighbor, according to Ukraine's Prosecutor General's Office.

"He knows what this aggression has brought, how full-scale the world's efforts must be to stop it, to restore Ukraine after the war," Zelenskiy said in his nightly video address after meeting Bloom.