CONCORD: United States President Joe Biden has called for Republican presidential candidate Donald Trump to be locked up "politically" for being a threat to democracy.

"We got to lock him up [...] politically lock him up. Lock him out. That's what we have to do," said President Biden as he exhorted Democrats at a New Hampshire campaign office to win the November 5 election.

Claiming that Trump wanted to disregard the safeguards of the US Constitution, the president warned that the country's democracy was at stake if the Republican candidate triumphed over Vice President and Democratic candidate Kamala Harris.

Trump, when he ran for president in 2016, repeatedly presided over rallies in which crowds chanted "lock her up," referring to then-Democratic nominee Hillary Clinton. He did not discourage them from that chant.

This year, during rallies for Harris, her crowds sometimes chant "lock him up," referring to Trump, who has been convicted of 34 felony counts related to covering up hush money paid to a porn star. He also faces charges of illegally trying to overturn his 2020 election loss.

But Harris shuts down the chants, saying the Justice Department will handle that issue while she seeks to beat the former president at the ballot box.