John Kerry
U.S. Secretary of State John Kerry has agreed to testify on Benghazi. State Department

U.S. Secretary of State John Kerry agreed to testify before the House committee investigating the 2012 attack on the diplomatic mission in Benghazi, Libya that killed U.S. Ambassador Chris Stevens and three other Americans, although a date for him to appear before the committee has yet to be worked out.

Kerry’s office sent a letter to U.S. Rep. Darrell Issa, R-California, chairman of the House Oversight & Government Reform Committee, informing Issa that Kerry has agreed to appear before the body, the Associated Press reported Friday. The committee has been holding hearings on the Benghazi attack, and Issa has also formed a special select committee on Benghazi.

It's unclear exactly when Kerry will appear before the House Oversight & Government Reform Committee. Those details are still being hashed out. The letter said diplomatic responsibilities preclude Kerry from appearing on May 29, the date of a subpoena sent by Issa’s committee. The State Department said Kerry can appear on either June 12 or June 20, AP reported.

The letter also suggested that there’s no need for Kerry to appear before the select committee if he’s going to testify before the House Oversight & Government Reform Committee.

Issa is the Republican leading the charge accusing the White House of covering up the circumstances that led to the attack on the mission.