Donald Trump has chosen Republican representative Elise Stefanik to serve as United States ambassador to the United Nations, the president-elect says in a statement shared with Reuters.

"I am honoured to nominate chairwoman Elise Stefanik to serve in my cabinet as US ambassador to the United Nations. Elise is an incredibly strong, tough, and smart America First fighter," Trump said.

Stefanik, 40, a New York representative and House Republican Conference chair, has been a fierce Trump ally.

She could not be immediately reached for comment.

The United Nations has been planning for Trump's return and the cuts to US funding and engagement with the world body that are likely to come with his second term as president.

Trump has offered few specifics about foreign policy in his second term but supporters say the force of his personality and his "peace through strength" approach will help bend foreign leaders to his will.

He has vowed to solve the war in Ukraine and is expected to give support to Israel in its conflicts with Hamas and Hezbollah in the Gaza Strip and southern Lebanon.

Lee Zeldin has been appointed to head the Environmental Protection Agency. (AP PHOTO)

Trump also announced the appointment of Republican former Congressman Lee Zeldin, who often voted against legislation on green issues including a measure to stop oil companies from price gouging, to head the Environmental Protection Agency.

"He will ensure fair and swift deregulatory decisions that will be enacted in a way to unleash the power of American businesses, while at the same time maintaining the highest environmental standards, including the cleanest air and water on the planet," Trump said in a post on his social media platform Truth Social.

Trump, a Republican, will likely look to reverse many rules administered by the EPA on the burning of fossil fuels including one curbing carbon emissions from power plants and another slashing such emissions from vehicles.

Trump has said he plans to begin rescinding EPA and Transportation Department vehicle pollution rules on his first day in office and is considering paring back or eliminating EV tax breaks and other incentives.

Trump also plans to rescind California's ability to set its own vehicle emissions rules, as he did in 2019.

President Joe Biden, a Democrat, reinstated California's authority. Trump will also decide how to spend billions of dollars in EV charging grants.

As a candidate for New York governor in the 2022 election, Zeldin criticised the state's decision to join California's Zero Emission Vehicle program that vows to end the sale of gasoline-powered only vehicles by 2035.

Zeldin also pressed in that unsuccessful campaign for a reversal of New York's ban on fracking, a drilling technique opposed by many environmentalists in the state, saying it would create jobs.

"We will restore US energy dominance, revitalise our auto industry to bring back American jobs, and make the US the global leader of AI," Zeldin said on the X social media platform, using the acronym for artificial intelligence.

Zeldin will have to be approved by the Senate, which regained a Republican majority in this month's election.

By Katharine Jackson in Washington, D. C.