Maine Independent Senator Angus King is calling for strong support for Ukraine after Friday’s televised argument between Ukrainian President Volodymyr Zelensky and President Trump.

King appeared on 60 Minutes last night, where he said Congress needs to respond to avoid a foreign relations disaster.

“I think They have to start speaking up because if we persist in walking away from Ukraine, it will be the greatest geopolitical mistake this country has made since World War II,” said King.

King has been highly critical of President Trump and his polices, call Trump an existential threat to the Constitution.

On 60 Minutes, King said Congress needs to respond to avoid a foreign relations disaster.

“I always try to think of, you know, what’s the argument on both sides,” King said. “I cannot think of a rational argument for pulling our support from Ukraine.”

King has called a recent US vote in the UN shameful, after the U.S vote sided with Russia and North Korea against a resolution condemning Russia’s aggression against Ukraine.