US Interior Secretary Ryan Zinke will leave his post at the end of the year, the latest high-profile departure from President Donald Trump’s administration to step down while under investigation for alleged ethics violations.

Trump did not give a reason for Zinke’s departure but the former congressman from Montana has come under scrutiny for his use of security details, chartered flights and a real estate deal.

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. Ryan has accomplished much during his tenure and I want to thank him for his service to our Nation…….

— Donald J. Trump (@realDonaldTrump) December 15, 2018

“Ryan has accomplished much during his tenure and I want to thank him for his service to our Nation,” Trump said on Twitter.

Zinke has run the Interior Department overseeing America’s vast public lands since early 2017.

Mere days ago, as Ryan Zinke was dismantling wetland protections, his astronaut socks suggested how lightly he regards environmental protections. Photo: AAP

He has pursued Trump’s agenda to promote oil drilling and coal mining by expanding federal leasing, cutting royalty rates, and easing land protections.

A climate-change denier and avowed critic of “intrusive” environmental regulations, Zinke was among Trump’s most active Cabinet members.

He slashed huge wilderness national monuments in Utah to a fraction of their size and advocated offshore oil drilling in the Arctic, Pacific and Atlantic.

Zinke became a darling of the U.S. energy and mining industries and a prime target for conservationists and environmental groups.

-with AAP