Lara Trump, President-elect Donald Trump's daughter-in-law, has stepped down as co-chair of the Republican National Committee amid speculation she might fill a possible Senate vacancy in Florida.

Announcing her resignation on social media she said, "the job I came to do is now complete", citing the RNC's successes in fundraising and voter turnout.

She did not specify her next move, but some Trump allies have lobbied for her to replace Senator Marco Rubio, the president-elect's pick for secretary of state.

If he is confirmed as America's top diplomat by the Senate, Florida Governor Ron DeSantis would hand-pick a replacement to serve out the remainder of Rubio's six-year term, which ends in 2026.

In an interview with the Associated Press, Lara Trump said she would be open to taking over Rubio's seat.

"It is something I would seriously consider," she said. "If I'm being completely transparent, I don't know exactly what that would look like."

Elected as RNC co-chair in March, Trump was hand-picked by her father-in-law - yet another indication of his iron-clad grip on the Republican party.

Alongside her husband, Eric, and his older brother Don Jr, Lara Trump emerged as one of the most prominent campaign surrogates for Donald Trump's White House bid this year.

"Serving as the GOP co-chair throughout the course of the most consequential election in American history has truly been the honor of my life," she wrote on X, formerly Twitter. She also thanked her father-in-law, writing: "we are so proud of you, and I'm grateful you trusted me in this position."

Several Republicans, including Senator Rick Scott of Florida, have publicly supported her as Rubio's replacement in the Senate.

Last month, Maye Musk, the mother of close Trump ally Elon Musk, offered Lara Trump an explicit endorsement for Senate, writing on X: "The next senator for Florida should be [Lara Trump]. The Senate is an old man's club. We desperately need a smart, young, outspoken woman who will reveal their secrets."

Elon Musk replied to the post: "Lara Trump is genuinely great."

The Florida Senate seat would be up for election again in 2028.