“And her letter will make absolutely clear the desire of this department, her personal desire to cooperate closely with the committee and with all members of Congress, both in their document requests, in their requests for witnesses for their hearing, because we share the same goal: We want to get to the bottom of precisely what happened and learn any lessons that we need to learn from it. We’re taking this very, very seriously.”

Asked how much information the department will be able to share while the FBI investigation is ongoing in Libya, Nuland said as much as possible.

“Her response back today will make clear that we are determined to work with the Congress, that we will send folks to their hearing,” she said. “We are now working through all of the documents, all of the information that is available to us in this department. We will see where we are on the 10th, but it is our intention to cooperate fully.”

The letter from the congressmen for the first time reveals an April 6 attack against the Consulate in which two former security guards threw homemade improvised explosives over the fence of the compound.

The letter also says militants made no secret of their intention to target Americans in Libya.

On May 22, a warning message was posted on Facebook that a rocket-propelled grenade attack against the Red Cross offices in Benghazi would be followed by a “message for the Americans disturbing the skies over Derna.” A separate threat was made the following month against Ambassador Christopher Stevens that mentioned his morning run with a security detail, complete with a stock photo of the late ambassador.

Asked if the State Department may have allowed too much leeway to Stevens to set his own security, Nuland said no.

“Ambassadors don’t call the local security posture,” Nuland said. “It’s worked out with Washington, with the post. It’s not something you can do yourself.”