The State Department's rejection of "repeated requests for increased security in Benghazi" came amid "a clear pattern of security threats" in the five months leading up to the attack on a U.S. diplomatic post in Libya, a Tuesday letter from House Republicans obtained by CNN reads.
"The attack that claimed the Ambassador's life was the latest in a long line of attacks on Western diplomats and officials in Libya in the months leading up to September 11, 2012," the letter from Reps. Darrell Issa and Jason Chaffetz to Secretary of State Hillary Clinton reads.
The Republicans demanded answers to several questions and testimony at a hearing next Wednesday -- the only hearing on any matter scheduled so far in the 35 days remaining until Election Day.
"Multiple U.S. federal government officials have confirmed to the Committee that, prior to the September 11  attack, the U.S. mission in Libya made repeated requests for increased security in Benghazi," the letter continued. "The mission in Libya, however, was denied these resources by officials in Washington."
Clinton wrote a letter in response on Tuesday, explaining that she had created a review panel and looks "forward to working with the Congress and your Committee as you proceed with your own review."
The secretary of state did not directly respond to the questions posed in the letter, but said an additional response would be coming.
"We will also address the specific questions in your letter and the document requests in Congressman Chaffetz's letter as expeditiously as possible, while taking into account any necessary measures to protect classified information," she wrote.
Earlier in the day, State Department spokeswoman Victoria Nuland said the department "will send folks to their hearing."
Issa is chairman of the House Oversight and Government Reform committee, and Chaffetz oversees the national security subcommittee. Chaffetz is also a top surrogate for the Romney campaign.
The September attacks claimed the lives of the U.S. ambassador to Libya and three others.
The day after the incident, Clinton described the Benghazi attack and a protest in Cairo, Egypt "as a response to inflammatory material posted on the Internet," referencing a controversial film trailer mocking the Muslim faith which was posted online.
Some Republicans, including House Intelligence Committee Chairman Mike Rogers, have said the administration left out important details in their description of the incident. Sen. John McCain said on CNN's "State of the Union" Sunday that the Obama administration's response was based on "either willful ignorance or abysmal intelligence."
Obama campaign senior adviser David Axelrod defended the response, saying it was based on "original information that that was given to us."
The letter demands information on the Benghazi post's security situation, communications between U.S. officials in Libya and Washington, as well as testimony next week from State Department officials.
Among the questions for the State Department to answer are any requests for increased security from the U.S. operation in Libya, "whether in general or in light of specific attacks," as well as whether the State Department was aware of prior security threats and its response.
The letter outlines "a clear pattern of security threats that could only be reasonably interpreted to justify increased security for U.S. personnel and facilities in Benghazi."
"Weeks before" the attack, "the unarmed Libyan guards... were being warned by their family members to quit their jobs guarding Consulate Benghazi because there were rumors in the community of an impending attack," the letter reads.
It also notes previous attacks and threats against the International Committee of the Red Cross, British diplomats, U.S. posts, and the U.S. ambassador. In addition to Benghazi, the letter notes events in the Libyan capital of Tripoli.
Asked Tuesday morning whether Clinton should testify if asked by Republicans, House Democratic leader Nancy Pelosi said, "I think that it would be appropriate for the Republicans, if they have important work to do, to call the House back into session and come here and deal with the full array of questions -- domestically and internationally."
While most lawmakers are out of town campaigning for reelection, the House is in "pro forma" session and no votes are expected until mid-November.
"I think it kind of curious that they want the House to be functioning, but they don't want it to be in order," Pelosi said. "Functioning when they want to challenge the administration, but not in order to do the work of the American people."
House Democratic Whip Steny Hoyer acknowledged that some legitimate questions had been raised about security issues but whether or not Clinton should testify was up to her.
"I think the leader said it well," he said. "We ought to be doing business here, not just selectively for political aims, but for the American people, not the politics."