UPDATED at 6:45 PM EST: This story originally stated that Col. Steve Warren would be the new press secretary for the Pentagon. After publication, Defense News learned Warren will be taking on a roll with the Defense Department, but not as the press secretary. This story has been updated to reflect the new information. 

WASHINGTON — Defense Secretary Jim Mattis is expected to tap Army Col. Steve Warren, a former spokesman for Operation Inherent Resolve, as a key media advisor.

Warren will retire out of active duty to take the spot, according according to a defense official speaking on background. The Pentagon is waiting for Warren's retirement to clear before making any formal announcement, the official said. The news was first reported by the Washington Examiner

Warren worked in the Pentagon as the Director of Press Operations from 2012-2015. For the first half of 2015, the Pentagon was without a spokesman, leaving Davis to fill the void until Peter Cook arrived over the summer. In late 2015, Warren was moved to Baghdad to be the department's spokesman for OIR.

During his time in the Pentagon and Baghdad, Warren established a reputation as someone who would be frank with reporters, and was known for mixing pithy soundbites with operational information.

The Pentagon has been without a spokesman since Cook stepped down at the change of the administration, and there are concerns about a broad move across DoD that officials are becoming less willing to talk to the press.

Almost two months after taking office, Mattis has yet to address the media outside of a few short comments to reporters while abroad. And in a March 1 memo, Chief of Naval Operations Adm. John Richardson warned against "sharing too much information publicly."

Shawn Snow with Military Times contributed to this report.