House Oversight and Government Reform Committee Chairman Darrell Issa has issued a subpoena to depose the ambassador charged with leading the review of the attack in Benghazi that killed four Americans.
Issa announced Friday that he will demand a deposition from Thomas Pickering, who along with Adm. Mike Mullen led the Accountability Review Board that did a report on security at the diplomatic post in Benghazi.
The subpoena requires Pickering to appear for a deposition on May 23.
Pickering has volunteered to testify publicly in front of the Oversight Committee. Issa says that isn't enough, and wants to interview Pickering before the committee holds a hearing with him.
In a May 16 letter to Issa, Pickering and Mullen wrote that the Oversight Committee's request for private interviews ahead of a hearing were "highly unusual in the context of senior officials who are not in fact witnesses but instead are reporting on their own independent review."
In the letter, Pickering and Mullen said they would be willing to testify in Congress on May 28, June 3 or another date of Issa's choosing.
A request to a State Department spokesperson for comment on the subpoena was not immediately returned.