"We're leaving office, but we're not leaving the fight," Biden said ... following Donald Trump's inauguration. Allison Robbert/AFP via Getty Images He said he hopes his staffers look back ...

open image in gallery President Joe Biden and President-elect Donald Trump rode in the presidential motorcade to the Capitol on Monday, per tradition (Getty Images) Upon meeting at the White House ...

The relationship between Biden and Trump has always been fraught ... but we’re not leaving the fight.” He shook hands and took photos before walking toward the hulking government plane ...

Trump also suggested that his time in the public life is not over. "I will always fight ... of Joe Biden's inauguration as the 46th U.S. president later in the day. (Eric Thayer/Getty Images ...