Rep. Luis Gutierrez (D-IL) on Wednesday said President Donald Trump’s Monday press conference with Russian President Vladimir Putin in Finland was “nothing short of treasonous” and called on Congress to relieve Trump of his duties.

Gutierrez, one of the first House Democrats to support Trump’s impeachment, claimed that at Monday’s Helsinki Summit, “the world witnessed the single worst performance by an American President on the world stage in world history.”

The Illinois Democrat added that the “disgraceful” performance “was the culmination of the worst week an American President has ever had” and “nothing short of treasonous.”

“This body, the House, the institution that I love so much and have served for more than 25 years cannot be sullied or diminished by this President and his inability to see the facts about the attack on the United States,” Gutierrez said. “As a body, we must take action to relieve the President of his duties.”

Gutierrez, who signed on to the Articles of Impeachment that House Democrats introduced in November, also said he believes Trump is “a threat to American Democracy” and has already begun consulting with his colleagues “about whether those Articles of Impeachment can be expanded and updated to include the betrayal witnessed by the American people and the world this week.”

He also vowed to “redouble” his efforts to prevent House Republicans from obstructing justice and undermining the FBI.

“And while it is already a full-time job, I will redouble my efforts to prevent the House of Representatives from taking actions to actively obstruct justice and undermine law enforcement and the FBI, while seeking to give the President cover and relief from a genuine, thorough investigation into the attack on our country by the Russians in 2016 and the attacks that are continuing to this day,” Gutierrez said.