The House Benghazi committee has issued a subpoena to a senior Pentagon official who criticized the GOP-led panel for making costly and unnecessary requests to the Defense Department.

Stephen Hedger, an assistant secretary of defense, will be interviewed under oath next week. Hedger claimed in a letter to the committee that officials could not find one of the requested witnesses — a drone sensor operator who identified himself on talk radio as "John from Iowa" — despite expending "significant resources" to do so.

The committee interviewed the drone operator this week.

Rep. Trey Gowdy, chairman of the Benghazi panel, said Hedger "will now have the opportunity to detail exactly what 'resources' he 'expended' and how."

Rep. Elijah Cummings, the committee's senior Democrat, called the subpoena an "abuse of authority."