Former Secretary of State Hillary Clinton agreed Monday to testify once, but not twice, before the special House committee investigating the 2012 attacks on the US Consulate in Benghazi, Libya.

Clinton attorney David Kendall, in a letter to the committee released by the Democrats, said Clinton could appear the week of May 18, as scheduled. But he rejected the committee's request that Clinton testify at the first hearing about her email records and at a separate hearing later about events surrounding the Benghazi attacks.

Kendall said the committee should cover both topics the same day, according to (USA Today).

"The Secretary is fully prepared to stay for the duration of the committee's questions on the day she appears," Kendall wrote to Rep. Trey Gowdy, R-S.C., chairman of the special committee.

Gowdy has said committee members aren't willing to question Clinton about Benghazi until they're sure they have all relevant State Department emails and documents. Gowdy has challenged whether all Benghazi-related emails stored on a server at Clinton's private residence were provided and has questioned her use of a private email account to conduct official government business.

Clinton, a Democratic candidate for president in 2016, was secretary of State when four Americans were killed, including Ambassador Christopher Stevens, in the Sept. 11, 2012, attacks. The House voted one year ago this week to create the special panel to investigate security lapses surrounding the attacks, the military's delayed response and whether the Obama administration initially downplayed the incident for political reasons.