State Natural Resources Commissioner Dan Sullivan is resigning amid speculation he'll run for an Alaska U.S. Senate seat next year.
The news comes as another Republican, Lt. Gov. Mead Treadwell, officially launched his campaign for Senate on Thursday.
Sullivan plans to resign effective Sept. 24. In his resignation letter to Gov. Sean Parnell, he says he intends to seek ways to serve his fellow Alaskans as he explores "new opportunities and challenges" in the next phase of his life.
Sullivan was returning from a conference returning from a conference in Asia and not immediately available for comment.
Sullivan was appointed DNR commissioner in 2010; before that, he served as Alaska attorney general and in the administration of President George W. Bush.
He deployed to Afghanistan in July after being recalled to active military duty.
Parnell spokesperson Sharon Leighow says the governor will appoint an interim replacement by Sept. 24 and then will conduct a search for a permanent commissioner.
Channel 2's Austin Baird contributed to this story