Julie Turkewitz and Coral Davenport

New York Times News Service

Interior Secretary Ryan Zinke, a key figure in President Donald Trump’s sweeping plan to reshape the nation’s environmental framework, resigned under pressure Saturday as he faces ethics investigations into his business dealings, travel and policy decisions.

“Secretary of the Interior @RyanZinke will be leaving the Administration at the end of the year after having served for a period of almost two years,” Trump wrote on Twitter. “Ryan has accomplished much during his tenure and I want to thank him for his service to our Nation.”

The president said he would name a replacement this coming week.

Zinke is the latest Trump official to exit an administration plagued by questions of ethical conflict. His departure comes as Trump has begun a shake-up in his administration. In early November, the president fired Attorney General Jeff Sessions, and last weekend he announced his chief of staff, John Kelly, was leaving.

In one of the final acts of Kelly’s tenure, his team told Zinke that he should leave by year’s end or risk being fired in a potentially humiliating way, two people familiar with the discussion said.

Trump has been looking at replacing a number of other Cabinet officials.

He has been telling associates for weeks that Commerce Secretary Wilbur Ross will be leaving now that the midterm elections are over, and he has frequently complained about Betsy DeVos, the education secretary.

The homeland security secretary, Kirstjen Nielsen, is seen as likely to depart soon.

Trump is aware the confirmation processes for any new nominees are likely to be more contentious in the second half of his term, as he faces re-election.

Zinke, a former Montana congressman and member of the Navy SEALs known for riding an Irish sport horse through Washington, D.C. on his first day in office, oversaw mineral extraction and conservation on roughly 500 million acres of public land.

He had become the subject of several federal investigations, one of which his department’s top watchdog has referred to the Justice Department, a potential step toward a criminal investigation.

The inquiries include an examination of a real estate deal involving Zinke’s family and a development group backed by the Halliburton chairman, David Lesar. Zinke stood to benefit from the deal, while Lesar’s oil services company stood to benefit from Zinke’s decisions on fossil fuel production.

Zinke has repeatedly denied wrongdoing.

“I love working for the President and am incredibly proud of all the good work we’ve accomplished together,” he said on Twitter. “However, after 30 years of public service, I cannot justify spending thousands of dollars defending myself and my family against false allegations.”

Zinke’s exit follows that of the other major architect of the Trump administration’s environmental policies, Scott Pruitt, the administrator of the Environmental Protection Agency.

Pruitt, known for his aggressive rollback of environmental regulations, resigned in July amid questions about alleged spending abuses, first-class travel and cozy relationships with lobbyists. Among other actions, Pruitt came under fire for reaching out to the chief executive of Chick-fil-A with the intent of helping his wife open a franchise.

Beyond examining the real estate deal, the Interior Department’s inspector general had faulted Zinke for allowing his wife, Lola, to travel in government vehicles, contrary to department policy, and chided him for using $12,000 in taxpayer money to take a charter plane after a talk to a hockey team owned by one of his biggest donors.

The inspector general has been examining the secretary’s decision to block two Native American tribes from opening a casino in Connecticut after his office received heavy lobbying from MGM Resorts International.

Delaney Marsco, ethics counsel at the Campaign Legal Center, a nonpartisan watchdog group, said Zinke’s actions had sometimes been overshadowed by Pruitt’s more obvious fumbles. That let the secretary operate in an “ethical Wild West,” she said.

“There are these laws and these ethical norms that are being blown to bits by these Cabinet secretaries,” Marsco said. “And that’s the pattern, the problem, that keeps us up at night.”