Gina McCarthy, the White House climate adviser, has told people that she will step down in the coming months because she is frustrated by the slow pace of climate progress.

Friends and colleagues said that Ms. McCarthy was expected to remain in her position for about a year.

One person familiar with Ms. McCarthy's plans said that President Biden asked her to stay on. Ms. McCarthy denied to others that she was leaving imminently and INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals INRDeals Ali Zaidi is expected to succeed her.

Ms. McCarthy did not respond to questions about her plans. The reports were called untrue by a White House spokesman.

There are no personnel announcements to make at this time.

Ms. McCarthy was tapped by Mr. Biden to lead his ambitious climate agenda, which calls for cutting the nation's greenhouse gas emissions roughly in half by the end of this decade.

His plans have been put on hold because of opposition from Republicans and from Senator Joe Manchin III, Democrat of West Virginia, who represents a crucial swing vote in the evenly divided Senate.

The Supreme Court is expected to rule soon on Mr. Biden's plans to use executive authority to impose tough new rules on greenhouse pollution from power plants and automobiles.

The war in Ukraine has caused gasoline prices to go up, prompting Mr. Biden to take steps that are against climate activists. He released a record amount of oil from the Strategic Petroleum Reserve, pleaded with oil and gas companies to do more drilling, and temporarily loosened environmental rules to allow the sale of gasoline with a blend of corn- and soy-based fuels during the summer months.

The UN report warned that time is running out for nations to pivot away from fossil fuels or face a future of climate catastrophe.

One person said that Ms. McCarthy was in beleaguered mode because she was worried about the political and legal challenges facing the administration's climate plans. Others said she had talked about the difficulties of being away from her husband.

Ms. McCarthy insists that she is still optimistic about the chances of climate legislation passing this year. She said at a recent event in Washington that she thought a bill would move this fall.

Ms. McCarthy was a chief architect of the president's climate change policies.

After the election of Donald J. Trump, Ms. McCarthy became head of the Natural Resources Defense Council, which sued the Trump administration more than 100 times.

Ms. McCarthy was charged with leading a whole-of-government approach to addressing climate change. She wanted Congress to pass new climate laws that would not be rolled back by a future president and would ensure a steady drop in the nation's greenhouse emissions.

Zolan Kanno-Youngs reported.