AP Photo/Susan Walsh
President Donald Trump, center, hosts a reception for House and Senate leaders in the the State Dining Room of the White House in Washington, Monday, Jan. 23, 2017.
Trump made the comments during a meeting with congressional leaders on Monday. House Speaker Paul Ryan and Senate Majority Whip John Cornyn were in attendance, according to Politico. Cornyn told the publication that Trump rehashed the long-debunked claim.
Cornyn added: "I didn't pay a lot of attention to it. I was ready to move on to some policy issues. I didn't anticipate that discussion."
Trump appeared to be echoing unsubstantiated claims he made in November. At the time, three states in which Trump made baseless claims about voter fraud - Virginia, New Hampshire, and California - denied the allegations. Multiple fact-checkers have also debunked the claims, while officials in a wide variety of states reported little to no violations.
Clinton, Trump's former Democratic rival in the presidential election, secured nearly three million more individual votes than Trump. Trump, now the 45th US president, won 304 electoral votes, easily surpassing the 270 needed to win the White House.
Trump has bristled at losing the popular vote, after an election that was punctuated by massive nationwide protests immediately following his win and again after his inauguration on Friday.