U.S. Secretary of State Hillary Rodham Clinton, left, meets with Libyan President Mohamed Magariaf, right on Monday in New York. (David Karp/AP)

Republican lawmakers demanded Wednesday that the Obama administration disclose details about the Sept. 11 attack on U.S. compounds in eastern Libya that killed an ambassador and three other government employees.

The requests for information about the assault, including any cables about security written by slain Ambassador J. Christopher Stevens, underscored the extent to which the incident has become a political liability for the White House during the final stretch of President Obama’s reelection campaign.

Lawmakers are asking whether the administration overlooked warning signs about the threat level in Libya, and some have suggested the security at the U.S. installations in Benghazi was inadequate.

Senior administration officials, including Secretary of State Hillary Rodham Clinton and Director of National Intelligence James Clapper, have briefed Congress. But details on the events in Benghazi are still being assembled.

After initially describing the attack as a spontaneous act of mob violence in response to a video that disparaged Islam, administration officials in recent days have begun to suggest it was a well-planned terrorist attack.

Clinton mentioned the Benghazi assault Wednesday during a speech at the U.N. General Assembly about the rise of extremist militants in North Africa. She did not specifically ascribe the attack to al-Qaeda in the Islamic Maghreb, the African offshoot of the terrorist organization, but she said the violent deaths of American officials underscored the importance of defeating the group.

“With a larger safe haven and increased freedom to maneuver, terrorists are seeking to extend their reach and their networks in multiple directions,” Clinton said, according to an official transcript of her remarks. “And they are now working with other violent extremists to undermine the democratic transitions underway in North Africa, as we tragically saw in Benghazi.”

U.S. counterterrorism chief Matthew Olsen told the Senate Homeland Security and Governmental Affairs Committee last week that analysts are exploring whether al-Qaeda’s African branch played a role in the attack. Investigators are also looking for evidence linking the assault to leaders of Ansar al-Sharia, a loose coalition of hard-line militants with a strong presence in Libya.

Republican congressmen took the administration to task for what they called contradictory statements about the Benghazi raid and initial information portraying it as a protest that turned violent.

“This seems like a pre-9/11 mindset — treating an act of war solely as a criminal matter,” a group of 10 congressmen wrote Wednesday in a letter to the president, referring to the 2001 terrorist attacks in the United States.

Sens. Johnny Isakson (Ga.) and Bob Corker (Tenn.), GOP members of the Foreign Relations Committee, sent a letter Tuesday to Clinton expressing concern about the “lack of security preparations made despite a demonstrable increase in risks to U.S. officials and facilities in Benghazi.” The senators asked to see any relevant cables that Stevens wrote in the days before he was killed.

The State Department has launched a type of probe called an accountability panel. The FBI is conducting a separate criminal investigation of the incident. Citing the inquiries, administration officials have provided few new details about the Benghazi raid in recent days. U.S. Ambassador to the United Nations Susan Rice made the most extensive remarks about the attack four days after the deaths. Her early accounts have come under scrutiny because they suggested that U.S. government officials did not believe the assault had been well planned or coordinated.

“We look forward to a timely response that explains how the U.S. ambassador to the United Nations could characterize an attack on a U.S. consulate so inaccurately,” Sen. John McCain (Ariz.) and three fellow Republican senators wrote Wednesday in a letter to Rice.