"I think every single colleague of mine agrees there is impeachable offenses, that's one thing that we all agree on," she said.
Nadler said in December he believed federal prosecutors had accused the president of impeachable offenses in dealings with his former lawyer Michael Cohen, who pleaded guilty to lying to Congress and to committing campaign finance violations at the president's direction.
"Whether they are important enough to justify impeachment is a different question, but certainly they'd be impeachable offenses," Nadler told CNN. The president has denied any wrongdoing and has accused Cohen of lying. Nadler's office did not respond to a request for comment Wednesday.
Most Americans do not support impeachment, though nearly two-thirds of Democrats are in favor, polls show. In a Quinnipiac University poll released on Tuesday, 59 percent of American voters said Congress should not begin impeachment proceedings.
In the same poll, nearly two-thirds of voters said Trump committed crimes before becoming president. Voters are split over whether Trump has committed crimes while president.
Top Democrats including Pelosi have said that impeachment talks are contingent on the findings of special counsel Robert Mueller, who is leading a Justice Department investigation into the president's 2016 campaign.
That investigation, which some expect to conclude soon, has resulted in a number of convictions and guilty pleas from those in the top echelons of the president's political orbit, including his former campaign chairman and his former national security advisor.
WATCH: How to impeach the President of the United States