Biden compares Russian invasion to Tiananmen Square

US President Joe Biden on Friday compared Russia's invasion of Ukraine to China's crushing of protests in Tiananmen Square in 1989, speaking during a visit to Poland near the border with Ukraine.

Biden also referred to Russian President Vladimir Putin as "a man who, quite frankly, I think is a war criminal", adding: "And I think we'll meet the legal definition of that as well."

Biden spoke at meetings with US soldiers stationed in Poland close to the border and with aid workers helping to deal with the massive refugee crisis caused by the conflict in Ukraine.

The US president said he would have liked to see the devastation caused by the conflict "first hand".

"They won't let me, understandably I guess, cross the border," he said.

Biden praised Ukrainians for showing "backbone" in their resistance against Russia, giving the example of "a 30-year-old woman standing there in front of a tank with a rifle".

"I mean, talk about what happened to Tiananmen Square. This is Tiananmen Square squared," he said.