Biden is in Ukraine in a surprise visit. He has pledged another $460 million in Ukraine assistance.

One year later, Kyiv stands,” Biden said. “And Ukraine stands. Democracy stands.”

The US will back Ukraine in its fight against Russia for "as long as it takes," he said.

"We have every confidence you're going to continue to prevail," he said.

US Secretary of State Antony Blinken announced a new package of security assistance for Ukraine valued at $450m (£373m), including ammunition for howitzers and the Himars rocket system, Javelin missiles, and air surveillance radars.

The US will also provide Kyiv with an extra $10m in emergency assistance "to keep Ukraine's energy infrastructure up and running", Mr Blinken said.

Today is President's day in America.