President Donald Trump took a shot at House Speaker Nancy Pelosi during a Fox News interview in Normandy, France, on Thursday shortly before he attended a commemoration of the 75th anniversary of D-Day.

"Nancy Pelosi, I call her Nervous Nancy, Nancy Pelosi doesn't talk about it. Nancy Pelosi is a disaster, OK?" Trump said. "She's a disaster. Let her do what she wants, you know what? I think they're in big trouble."

Pelosi refused to take the bait — at least for now. "I don't talk about the president while I'm out of the country," she said Thursday from Normandy. "That's my principle."

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President Donald Trump took a shot at House Speaker Nancy Pelosi during a Fox News interview in Normandy, France, on Thursday shortly before he attended a commemoration of the 75th anniversary of D-Day.

Sitting in front of a cemetery of American war dead, Trump argued that Pelosi's leadership and the Democratic Party's investigations into him were a "disaster." And he took the opportunity to debut a nickname for Pelosi.

"Nancy Pelosi, I call her Nervous Nancy, Nancy Pelosi doesn't talk about it. Nancy Pelosi is a disaster, OK?" Trump said during an interview with the Fox News host Laura Ingraham. "She's a disaster. Let her do what she wants, you know what? I think they're in big trouble."

When asked about the comment, Pelosi, who is also in Normandy, told reporters that she had a policy of not criticizing the president while on foreign soil.

"I don't talk about the president while I'm out of the country," she said. "That's my principle."

Read more: 'Impeachment is inevitable': More Democrats push for impeachment as Nancy Pelosi accuses Trump of 'engaging in a cover-up'

Pelosi and Trump have traded increasingly personal attacks over the past few weeks, as pressure from Democrats builds to initiate an impeachment inquiry into the president.

"In plain sight, in the public domain, this president is obstructing justice, and he's engaged in a cover-up, and that could be an impeachable offense," Pelosi said late last month, prompting Trump to abruptly cancel a meeting with Democratic leadership.

On Wednesday, Pelosi told senior Democratic lawmakers she wanted to see Trump "in prison," Politico reported.