Two of President Trump's challengers for the 2020 Republican presidential nomination called for his impeachment during a Tuesday evening debate.

Former Massachusetts Gov. Bill Weld (R) and former Rep. Joe Walsh (R-Ill.) agreed that Trump needs to be removed from office during the event, which was hosted by Business Insider hours after House Speaker Nancy Pelosi (D-Calif.) announced the formal launch of an impeachment inquiry into Trump.

"The president of the United States will be impeached very, very soon. The president of the United States will deserve to be impeached very, very soon," Walsh said in his opening statement.

"I'm not debating Bill Weld," Walsh added. "The problem is an unfit president in the White House who took a divided country and is it is dividing it even more."

Weld similarly appeared supportive of impeachment proceedings.

"Cold hard facts from evidence under oath will have been hammered out in those proceedings," he said. "I think it's a nightmare for Donald Trump, and he has no way of stopping it before the election."

Neither Trump nor fellow primary challenger former South Carolina Gov. Mark Sanford (R) attended the event. Moderators said that Trump did not respond to their invitation and Sanford had a scheduling conflict.

Sanford, Weld and Walsh face an uphill battle in their challenges to Trump for the 2020 GOP nod. Polling has showed broad support for the president among Republicans, and several state parties have voted to cancel their primary elections in support of him.

Pelosi on Tuesday announced the impeachment inquiry after reports that Trump had pushed Ukrainian President Volodymyr Zelensky to investigate former Vice President Joe Biden and his son after withholding aid from Ukraine.

The White House on Wednesday released a partial transcript of the July call in which Trump said "Biden went around bragging that he stopped the prosecution so if you can look into it ... It sounds horrible to me."

The president said he withheld aid because he wanted other countries to give more money to help Ukraine.

He has slammed the inquiry as a "witch hunt" and denied any wrongdoing.

Pelosi's announcement followed a new wave of support for impeachment proceedings from House Democrats following the Ukraine revelations.