The former Massachusetts governor joins the crowded field of Democrats seeking the 2020 presidential nomination.
The acting U.S. ambassador to Ukraine revealed the new information while testifying at the House impeachment hearings.
The two presidents will meet as the first public hearing of the House's impeachment inquiry unfolds.
The former South Carolina governor focused on the national debt in his campaign, calling Trump the "king of debt."
NBC's Savannah Guthrie grilled the former U.S. ambassador to the United Nations about the impeachment inquiry into the president.
The president spoke at Madison Square Park ahead of the 100th annual Veterans Day Parade.