Canadian singer Celine Dion said on Saturday that use of her "Titanic" movie theme song "My Heart Will Go On" at a Montana rally of Republican presidential candidate Donald Trump the previous night was not authorized.

The song and its video clip were played at the former U.S. president's rally in Bozeman, Montana on Friday on the big screen near the stage.

"In no way is this use authorized, and Celine Dion does not endorse this or any similar use," the singer's social media account, said, adding: "And really, that song?"

Dion, a five-time Grammy winner, is best known for that song.

She had reportedly refused to perform at Trump's January 2017 inauguration when the former president took office after winning the 2016 election.

Trump held the rally on Friday to support a Republican candidate for Senate.

In it, he attacked Vice President and Democratic presidential candidate Kamala Harris in personal terms while criticising her for not doing interviews or holding major press conferences since she took over after President Joe Biden ended his reelection campaign.