Former US Vice President Dick Cheney says he is voting for Democratic presidential nominee Kamala Harris.

Cheney was a Republican heavyweight, but has kept aloof from former president and current Republican nominee Donald Trump.

Cheney issued a statement on Friday expressing his support for Vice President Harris in the November election.

Cheney said Trump "tried to steal the last election using lies and violence to keep himself in power after the voters had rejected him." Trump supporters rioted in the Capitol on January 6, 2021, after the former president had disputed the election's result.

Cheney served as vice president under President George W. Bush.

He was seen as having a powerful influence in US politics in the aftermath of the September 11, 2001, terror attacks and during the Iraq War. He was sometimes cited as a "shadow president."

Earlier this week, his daughter Liz Cheney, who was once the No. 3 Republican in the US House of Representatives, expressed her intent to vote for Harris.

Their moves come after more than 200 former staffers, who worked for Republican presidents and senators before Trump became president, declared their support for the Harris campaign in an open letter released in late August.

But analysts say such anti-Trump moves by Republicans have so far been limited and that many in the party appear to be united under Trump.