The UN Security Council held an emergency meeting to discuss a wave of Russian airstrikes on several Ukrainian cities.
Among the sites hit was the Okhmatdyt children's hospital in Ukraine's capital, Kyiv.
During the emergency meeting, France's representative, Nicolas de Riviere, called it a "further entry in a list of war crimes" committed by Russia in Ukraine.
China also expressed concern over the strikes, but did not directly denounce Moscow.
Fighting in Ukraine "intensified and there have been brutal attacks from time to time that have claimed many victims. China is deeply concerned about this," said China's deputy ambassador to the UN, Geng Shuang.
Joyce Msuya, the acting head of the UN Emergency Relief and Works Agency (OCHA), said that the strike that hit the Okhmatdyt hospital was part of "a deeply concerning pattern of systemic attacks, harming healthcare and other civilian infrastructure across Ukraine."
"Intentionally directing attacks against a protected hospital is a war crime and perpetrators must be held to account," she said.
Russia is a permanent member of the UN body, meaning that it has a veto over Security Council resolutions. The other permanent members are China, France, the United Kingdom and the United States.
Also on Tuesday, a UN rights mission said that there was a "high likelihood" that the children's hospital in Kyiv took a direct hit from a Russian missile.
"Analysis of the video footage and an assessment made at the incident site indicates a high likelihood that the children's hospital suffered a direct hit rather than receiving damage due to an intercepted weapon system," said Danielle Bell, head of the UN Human Rights Monitoring Mission in Ukraine.
Biden and Ukraine's Zelenskyy to meet at NATO summit Thursday, White House confirms
US President Joe Biden and Ukrainian counterpart Volodymyr Zelenskyy will meet at NATO's 75th anniversary summit in Washington on Thursday to show "unwavering support" for Kyiv, the White House said.
"On Thursday afternoon, President Biden will meet with President Zelenskyy of Ukraine to discuss our unwavering support for Ukraine as it continues to defend itself from Russian aggression," White House Press Secretary Karine Jean-Pierre told a briefing Tuesday.
Scholz reaffirms Ukraine support ahead of NATO summit
Germany's chancellor, Olaf Scholz, has repeated his long-term support for Ukraine against Russia ahead of a NATO summit in Washington.
Scholz said he was keen to use the opportunity to restate the very clear message that "we will stand by Ukraine for as long as it takes."
He spoke about arms deliveries and a joint initiative recently agreed by the G7 the group of major industrialized democracies.
At its summit in Italy, the G7 agreed to finance a loan package of about $50 billion, partly using interest from frozen Russian state assets.
Scholz said that the measure was a clear sign of solidarity as well as a message to Moscow.
He said Russian President Vladimir Putin could not rely on "sitting out this war, so to speak, and waiting until support for Ukraine wanes."
Ukrainian President Volodymyr Zelenskyy has slammed Indian Prime Minister Narendra Modi's visit to Russia saying it has dealt a blow to peace efforts.
Zelenskyy's post included pictures of a missile strike that hit a children’s hospital in Kyiv on Monday.
"It is a huge disappointment and a devastating blow to peace efforts to see the leader of the world's largest democracy hug the world's most bloody criminal in Moscow on such a day," Zelenskyy wrote in a message on X, the platform formerly known as Twitter.
Modi met Putin on Monday, at the start of his two-day trip. He posted photos of his arrival in Moscow on X, in both Russian and English.
Modi said he was "looking forward to further deepening the Special and Privileged Strategic Partnership between our nations."
UN assessment says Russian strike 'direct hit' on children's hospital
Initial footage indicates that a Russian missile struck a children's hospital in Kyiv, the UN Human Rights Monitoring Mission in Ukraine said.
Danielle Bell, who heads the mission, said the footage shows a "missile launched by the Russian Federation... directly impacting the hospital."
She added that further investigation was necessary.
Russia denied responsibility for the hospital strike on Monday.
Ukrainian authorities, however, said Russia struck the hospital with a Kh-101 Kalibr missile.