Joe Biden appeared to muddle Ukrainians with Iranians in a gaffe during his most high-profile speech of the year.
The US President made the slip-up during a State of the Union address in which he warned “dictator” Vladimir Putin “has no idea what’s coming” after Russia ’s invasion of Ukraine.
Congressmen and women stood, applauded and roared, many of them waving Ukrainian flags and wearing the country's blue and yellow colours, as he delivered the speech.
The US President announced a ratcheting up of sanctions on Moscow, joining the EU and Canada in banning Russian planes from US airspace.
"Let each of us if you're able to stand, stand and send an unmistakable signal to Ukraine and to the world," Biden said.
"Putin's war was premeditated and unprovoked. He rejected efforts at diplomacy. He thought the West and NATO wouldn't respond. And, he thought he could divide us here at home… Putin was wrong. We were ready."
He was set to add: "Throughout our history we've learned this lesson - when dictators do not pay a price for their aggression, they cause more chaos. They keep moving.
“And, the costs and threats to America and the world keep rising.”
But in an embarrassing gaffe, the US President appeared to mix up Ukrainians with Iranians.
He said: “For our fellow Ukrainian-Americans, who forged a deep bond that connects our two nations, we stand with you.
“Putin may circle Kyiv with tanks, but he’ll never gain the hearts and souls of the Iranian people.
“He’ll never extinguish their love of freedom, and he will never weaken the resolve of the free world.”
Biden sought to unite Americans in solidarity with Ukraine in the speech while also focusing on his domestic economic agenda, including reintroducing elements of his stalled Build Back Better programme.
