Former President Donald J. Trump on Monday night made public what he has been discussing privately for days: He has settled on someone to replace Ronna McDaniel as the chair of the Republican National Committee, and wants his daughter-in-law, Lara Trump, to be the co-chair.

“The RNC MUST be a good partner in the presidential election,” Mr. Trump wrote in his statement. “It must do the work we expect from the national Party and do it flawlessly. That means helping to ensure fair and transparent elections across the country” and getting out the vote, he said.

He said he wanted his “friend” Michael Whatley, currently the chairman of the North Carolina Republican Party and the national committee’s general counsel, and “my very talented daughter-in-law, Lara Trump,” to serve as party leaders.

“Lara is an extremely talented communicator and is dedicated to all that MAGA stands for,” Mr. Trump said of his daughter-in-law, who is married to his middle son, Eric. “She has told me she wants to accept this challenge and would be GREAT!”

The statement came hours after The New York Times reported that Mr. Trump had told people he was considering endorsing Ms. Trump. The Times had previously reported that Mr. Trump wanted Mr. Whatley — a supporter of his false claims about widespread voter fraud — as the next R.N.C. chair.

Both the chair and co-chair are paid positions.

Mr. Trump cannot simply appoint them. An election must be called to replace Ms. McDaniel when she ultimately decides to step down. And despite Mr. Trump’s heavy influence over the party, his endorsement of Mr. Whatley in 2023 as co-chair was not enough to pull him across the finish line to win.