WASHINGTON (AP) – Anthony Principi, chairman of the commission that will review the newly released list of military base closings, has resigned his executive post with the drug manufacturer Pfizer Corp., The Associated Press has learned.

Principi, a former Veterans Affairs secretary, told the company Friday that he is stepping down in order to fully carry out his responsibilities as chairman of the Base Realignment and Closure Commission, a Pfizer spokesman confirmed.

“We’re very sorry to be losing Mr. Principi, but we respect his commitment to the commission and to the president and to the Congress in service of our country,” said the Pfizer spokesman, Paul Fitzhenry.

He said the reason centered on the time demands of the commission job.

Principi joined the company as a vice president in March, to run Pfizer’s Washington, D.C., office.

He is from California, a state that was hard hit in the previous four base closing rounds. Pfizer has a large research facility in Connecticut, a state hit hard by the Pentagon’s base closing recommendations released Friday.

Pfizer has labs in Groton, where the Pentagon has recommended closing the U.S. Naval Submarine Base, and a facility in neighboring New London.

Principi, a decorated Vietnam War veteran, once served as a chief counsel for the Senate Armed Services Committee and Senate Veterans Affairs Committee. He also has been a top official with defense contractor Lockheed Martin.