Now Trump’s interior secretary is facing an ethics inquiry after threatening GOP senators

The Interior Department's Office of the Inspector General opened a “preliminary investigation" into Interior Secretary Ryan Zinke after he placed phone calls to Sens. Lisa Murkowski (R-AK) and Dan Sullivan (R-AK) on behalf of Donald Trump.

Zinke last week contacted the Republican Senators after Murkowski failed to vote in favor of a motion to proceed on the GOP Obamacare replacement plan. Sullivan told the Alaska Dispatch News that Zinke brought up issues including nominating Alaskans to the Interior department and drilling in the Arctic National Wildlife Refuge.

Sullivan called the conversation “troubling,” adding “the message was pretty clear.”

"I'm not going to go into the details, but I fear that the strong economic growth, pro-energy, pro-mining, pro-jobs and personnel from Alaska who are part of those policies are going to stop," Sullivan told the News.

The OIG on Thursday sent a letter to Congressmen Frank Pallone (D-NJ) and Raúl Grijalva (D-AZ), who requested the inspector general “address a number of potential legal and ethical violations.”

"OIG is undertaking a preliminary investigation into this matter,” Deputy Inspector General Mary Kendall wrote.

Murkowski, who joined Zinke for a beer on Thursday, described her communication with the interior secretary as “not a very pleasant call.” But she told CNN’s Dana Bash on Thursday that she “did not take it as a threat.”

“[Zinke] and I have a pretty good relationship, very professional, a respectful one. My hope is that we're going to be able to continue to work on good, good energy initiatives for Alaskans,” she said.