WASHINGTON – The Biden government is expected to announce Thursday that it will advance a plan to fully restore the conservation of Alaska’s Tongass National Forest, one of the largest intact temperate rainforests in the world. The protection had been lifted by former President Donald J. Trump.

Agriculture Secretary Tom Vilsack, whose agency includes the United States Forest Service, is expected to release the news, according to two people who had been briefed on the matter and wanted to speak anonymously as it had not yet been released.

White House, Agriculture Department and Forest Service spokesmen did not respond to requests for comment on Wednesday evening.

Alaska lawmakers hoped the Biden government could restore protection to some parts of the fragile forest, but leave part open for logging.

Instead, the new plan will not only restore the old safeguards, but also add new safeguards, including an end to large-scale deforestation of scrap wood on the entire 16 million acres of the forest, according to those informed on the matter. It is also expected to include $ 25 million in federal spending on local sustainable development in Alaska for forest health improvement projects.

That money appears to be going in part to appease Republican Senator Lisa Murkowski, who is now playing a key role in negotiating a $ 579 billion bipartisan infrastructure bill that President Biden believes will be critical to advancing his economic agenda looks at. She has personally asked senior government officials to keep parts of the Tongass open for economic development, which she believes is critical to her home state.

At the same time, Mr Biden is trying to get through the most ambitious climate agenda any American president has ever imagined. With record droughts, forest fires and heat waves rocking western states, Mr Biden seeks to revive and strengthen the safeguards that Mr Trump was withdrawing and to reduce the pollution that is driving climate change.

This fall, Mr Biden plans to attend a conference of United Nations world leaders in Scotland to argue that the United States is leading the fight against global warming after four years of mocking climate science by the American president.

Environmentalists said the move to fully restore the protection of the Tongass could be a step to make this case a reality.

“This is the Biden administration on its way to the Glasgow summit this fall to reclaim climate leadership,” said Niel Lawrence, Alaska director of the Natural Resources Defense Council, an advocacy group.

The forest plays an important role in climate protection. Scientists point out that the Tongass provides an important service to the billions of people around the world who will likely never ever set foot in it: it is one of the largest carbon sinks in the world, storing about 8 percent of total carbon stored in the forests of the lower 48 states together.

The vast wilderness of southeast Alaska is home to more than 400 species of wildlife, fish, and shellfish, including nesting bald eagles, moose, and the world’s largest concentration of black bears. Between its snow-capped peaks, fjords and rushing rivers lie stocks of red and yellow cedar and hemlock, as well as Sitka spruces that are at least 800 years old.

Republicans and Democrats have been fighting over the Tongass for 20 years. The forest was severely cut down in the 1960s and 1970s, but in 2001 President Bill Clinton enacted the “Roadless Rule,” which blocked the road construction required for logging and mining much of the forest.

A few months before leaving office, Mr. Trump exempted the entire forest from “roadless rule” and presented a victory to the Republican leaders of Alaska, who argued that the southeastern part of their state needed economic recovery, logging and other developments The move was attacked by environmentalists and the majority of commentators, who formally submitted their opinions to the government.

Ms. Murkowski has criticized the idea of ​​restoring full protection to Tongass.

“Obviously, my strong, strong preference for an exception was that this roadless rule shouldn’t apply to the entire nine million acres,” Ms. Murkowski said in an interview last month.

The yo-yo aspect of Tongass politics makes it difficult for Alaskans, she said.

“It’s hard for the churches, it’s hard to plan,” she said. “There’s a local bank down there that can catch as fast as possible, you know. How do you know where to invest when you have such uncertainty that has lasted for so long? We have to try to put an end to this. “