President-elect Donald Trump has tapped House Republican Conference chair and longtime ally Rep. Elise Stefanik, R-N.Y., to serve as ambassador to the United Nations, a Trump transition official confirmed to NBC News on Monday. The nomination is Trump's first Cabinet pick for his second term in the White House.

Stefanik, who just won reelection to her seat, accepted Trump’s offer to be the next ambassador from the United States to the United Nations.

President-elect Donald Trump has offered Republican Rep. Elise Stefanik the job as US ambassador to the United Nations, two sources familiar told CNN on Sunday.