US President-elect Donald Trump has chosen representative Elise Stefanik to serve as his ambassador to the United Nations.

In a statement announcing his choice, Mr Trump said: “Elise is an incredibly strong, tough, and smart America First fighter.”

Ms Stefanik, 40, who serves as House Republican conference chair, has long been one of Mr Trump’s most loyal allies in the US House of Representatives, and was among those discussed as a potential vice presidential choice.

Born and raised in upstate New York, Ms Stefanik graduated from Harvard and worked in formerpPresident George W Bush’s White House on the domestic policy council and in the chief of staff’s office.

A close-up of Donald Trump with the American flag in the background
Elise Stefanik spent years positioning herself as one of Donald Trump’s most trusted allies (AP)

In 2014, aged 30, she became the youngest woman ever elected to Congress, representing upstate New York. She later became the youngest woman to serve in House leadership.

Ms Stefanik was known early in her tenure as a more moderate conservative voice, but she soon attached herself to the former president.

She became the House Republican conference chair in 2021.

Ms Stefanik spent years positioning herself as one of Mr Trump’s most trusted allies and endorsed him in the 2024 race before he had even launched his bid, and aggressively campaigned on his behalf during the Republican primary.

She saw her profile rise after her aggressive questioning of a trio of university presidents over antisemitism on campus led to two of their resignations — a performance Mr Trump repeatedly praised.

She also defended him vigorously in both of his impeachment trials.

Nikki Haley, who challenged Mr Trump for the Republican presidential nomination, was among those who previously held the UN ambassador role in his first term.