Former US Special Counsel Robert Hur spoke to the House of Representatives Judiciary Committee, which has been one of the panels conducting an impeachment inquiry into Biden, 81.
The officials declined to discuss exact timing of the expected US air drop of aid into Gaza, although two officials said it could happen in the coming days.
This year's physical comes as Biden, a Democrat, and former Republican President Donald Trump, 77, prepare to face off in a likely rematch in the Nov. 5 presidential election.