GENEVA, Mar 1 (Reuters) - US Secretary of State Anthony Blinken said on Tuesday (Mar 1) that Russian "crimes" in Ukraine are mounting by the hour, with strikes hitting hospitals, schools and homes, and called for holding perpetrators accountable.

Moscow faced increasing isolation on Tuesday as President Vladimir Putin showed no sign of stopping an invasion of Ukraine, where fierce fighting and Russian bombardment have killed dozens and sparked a refugee crisis.

"Russian strikes are hitting schools, hospitals, and residential buildings," Blinken said in a video message to the UN Human Rights Council. "Reports of Russia's human rights abuses and violations of international humanitarian law mount by the hour."

Blinken said that the Geneva forum's urgent debate on Ukraine set for Thursday, where a resolution brought by Kyiv and allies would set up an international probe into violations, is an "important step toward ensuring documentation and accountability".

"We must take steps to hold the perpetrators accountable," he added, invoking the need to act out of respect for "every victim of those crimes," he said.

The United States is looking closely at whether war crimes were committed during the Russian invasion of Ukraine and engaging with partners around the world on the issue, White House press secretary Jen Psaki said on Tuesday.

Uzra Zeya, US Under Secretary of State for Civilian Security, Democracy, and Human Rights, told reporters in Geneva that Russia's invasion was "resulting in a human rights and humanitarian catastrophe".

"If they are intentionally targeting civilians or civilian objects, that would be a violation of international humanitarian law," she said.

Zeya denounced what she called "the depravity of past Russian operations", including in areas of Ukraine's Donbass region, saying they were marked by extrajudicial killings, abductions, unlawful detentions and torture.