House Speaker Nancy Pelosi said Wednesday that President Donald Trump is “scared” of the impeachment inquiry she launched last week centered on a whistleblower complaint alleging he pressured Ukraine to help investigate former Vice President Joe Biden and interfere in the 2020 presidential election.

“I think the president knows the argument that can be made against him, and he’s scared,” Pelosi, D-Calif., told ABC News Chief Anchor George Stephanopoulos in an interview in her ceremonial office in the U.S. Capitol, which aired Thursday morning on "Good Morning America."

“And so he’s trying to divert attention from that to where [he’s] standing in the way of legislation,” she said.

Shortly before Pelosi sat for the interview with Stephanopoulos, the president dismissed the inquiry with an expletive and tweeted advice to Democrats to choose “a better candidate” than Hillary Clinton in 2020.

"The Do Nothing Democrats should be focused on building up our Country, not wasting everyone’s time and energy on [B***S***], which is what they have been doing ever since I got overwhelmingly elected in 2016, 223-306," Trump tweeted, referring to the electoral vote. "Get a better candidate this time, you’ll need it!"

“You say he’s scared … Did you hear the fear in his voice when you spoke with him on the phone last week?” Stephanopoulos asked about a Sept. 24 conversation Pelosi had with Trump hours before she launched the formal impeachment inquiry.

“I saw the surprise in his voice that he didn’t understand that I thought what he did was wrong,” Pelosi said, referring to Trump's call with Ukraine President Volodymyr Zelenskiy. “That he was undermining our national security, that he was undermining our Constitution by his actions and he was undermining the integrity of our elections. He just didn’t see it.”

Trump also dismissed Pelosi’s challenge to work toward bipartisan agreement to lower prescription drug costs and overhaul a trade agreement with Mexico and Canada – despite the Democrats’ newly launched impeachment inquiry.

“But now he’s calling you the ‘Do Nothing Democrats,’ says you can’t do it?” Stephanopoulos asked.

“Why can’t we do it? It’s up to him,” Pelosi said. “That was our pledge during the campaign, ‘For the People,’ we would lower the cost of prescription drugs. I think that the president wants to do that. So, I hope that he would cooperate. He does want the U.S., Mexico, Canada free trade agreement. So do we -- when we have assurances that there will be enforceability for America’s workers and America’s farmers. And we’re close. We’re on a path to yes,” she said.

More from the exclusive interview was broadcast on ABC's "Good Morning America" on Thursday.