President Donald Trump on Thursday withdrew his nomination of Rep. Elise Stefanik as U.S. ambassador to the United Nations.

Trump cited the razor-thin majority that Republicans hold in the House of Representatives for his decision to pull Stefanik's name from consideration by the Senate for the U.N. post.

The vote of Stefanik, a New York Republican, has repeatedly been crucial in helping the GOP caucus pass key legislation since the beginning of Trump's term in January.

The full Senate for nearly two months had held off on voting on her ambassadorship nomination, after it was recommended by the Foreign Relations Committee, because of concerns that her departure from the House would threaten Trump's legislative agenda.

The GOP caucus currently holds 218 seats in the House, with Democrats holding 213 seats.

Trump's move came days before two special elections in Florida on Tuesday to replace Republican congressmen who quit those seats to take posts in the Trump administration.

One of those lawmakers, former Rep. Matt Gaetz, was picked by the then-president-elect Trump in November to be U.S. attorney general. Gaetz withdrew from consideration by the Senate weeks later amid renewed focus on sexual misconduct allegations that had dogged him for years despite his denials of wrongdoing.

The other special election is being held to fill the seat recently held by former Rep. Mike Waltz, Trump's national security adviser.

Waltz is currently facing criticism for his Signal app account accidentally adding The Atlantic magazine editor-in-chief Jeffrey Goldberg to a text group that included top U.S. officials, among them Defense Secretary Pete Hegseth and Vice President JD Vance, and which discussed plans for American military attacks on Houthi targets in Yemen.

Trump, in a social media post Thursday, wrote, "As we advance our America First Agenda, it is essential that we maintain EVERY Republican Seat in Congress."

"We must be unified to accomplish our Mission, and Elise Stefanik has been a vital part of our efforts from the very beginning," Trump wrote in the Truth Social post. "With a very tight Majority, I don't want to take a chance on anyone else running for Elise's seat."

If Stefanik left the House, her seat would be filled by a special election in New York.

Trump did not say who he would now nominate for the U.N. ambassador slot.

But, he wrote, "There are others that can do a good job at the United Nations."

"Therefore, Elise will stay in Congress, rejoin the House Leadership Team, and continue to fight for our amazing American People," Trump said.

Stefanik previously was chair of the House Republican Conference, the No. 4 leadership position in the chamber, but resigned that role after Trump nominated her for the U.N. ambassadorship.

House Speaker Mike Johnson, R-La., in a tweet, said he would invite Stefanik "to return to the leadership table immediately." He did not say what position she would hold in the leadership.