U.S. President Joe Biden vowed to push on with his reelection bid on Monday, dismissing the concerns of some fellow Democrats on Capitol Hill and donors that his persistence could cost their party the White House and Congress in the Nov. 5 election.

Biden, 81, said any candidates who doubt his ability should challenge him at the Democratic National Convention in August — an effort that stands no chance of success unless he lets the delegates he won in primaries this year consider other candidates.

"The bottom line here is that I am not going anywhere," Biden said in a phone call he placed to MSNBC's Morning Joe program.