Joe Balash, left, on a visit to Arctic Village in June. Balash is the Interior Department official who has been leading the federal government’s planning process in advance of opening the Arctic Refuge to oil development. He resigned Monday. (Photo by Nat Herz / Alaska’s Energy Desk)

Assistant Interior Secretary Joe Balash, one of the highest placed Alaskans in the Trump administration, has resigned.

His boss, Interior Secretary David Bernhardt, announced it by tweet Tuesday afternoon.

Assistant Secretary Joe Balash announced today his plans to move on from @Interior and I stand with @POTUS in thanking him for his exemplary service to the American people. — Secretary David Bernhardt (@SecBernhardt) August 20, 2019

Balash was confirmed in 2017 as Interior’s assistant secretary for Land and Minerals Management. He oversees the Bureaus of Land Management and Ocean Energy Management. He’s been working to prepare for the first oil lease sale in the Arctic National Wildlife Refuge.

In his resignation letter, Balash does not cite a reason. He said he’s proud of the work he’s done, including lifting regulations on resource extraction industries, and the environmental work on ANWR.

“Implementing your executive orders promoting energy independence and economic growth are a career highlight that I will one day tell my grandchildren about,” Balash wrote in his letter, addressed to President Trump.

From the archives: Meet the Trump administration official whose signature could formally open ANWR to drilling.

In a brief phone call, Balash said he’s resigning to pursue another opportunity, which he said he’d describe at a later date. His resignation takes effect Aug. 30.

Balash grew up in North Pole and previously worked as Alaska’s commissioner of Natural Resources as well as chief of staff to U.S. Sen. Dan Sullivan.