WASHINGTON – Senior State Department officials acknowledged to Congress on Wednesday that they had turned down requests to send more U.S. military personnel to guard diplomatic facilities in Libya shortly before the Sept. 11 attack that killed the U.S. ambassador and three other Americans.

But Charlene Lamb, deputy assistant secretary in charge of diplomatic security, argued that security at the U.S. mission in Benghazi was appropriate for known threats related to the 11th anniversary of the Sept. 11 terrorist attacks in America.

“We had the correct number of assets in Benghazi at the time of 9/11,” Lamb testified. She said the consulate had five diplomatic security agents, plus several U.S.-trained Libyan guards and members of a local militia on standby, when the attack occurred.

The testimony came during a politically charged four-hour hearing of the Republican-led House Oversight and Government Reform Committee that focused on whether warnings were ignored before the attack, an issue that has put the Obama administration on the defensive in the heat of a presidential campaign.

Eric Nordstrom, the former regional security officer in Libya, testified that a few more armed Americans would not have repelled the organized nightlong assault by dozens of heavily armed extremists, which he called unprecedented in its “ferocity and intensity.”

But Nordstrom, who left Libya in July, sharply criticized his State Department supervisors for ignoring his concerns about the growing risk of armed militias and extremist groups in Benghazi.

Nordstrom said he was frustrated by “a complete and total absence of planning” to improve security.

“When I requested assets, I was criticized. It was a hope that everything would get better.”

Lt. Col. Andrew Wood, who headed a 16-member U.S. military team assigned to protect the embassy in Tripoli, said decision makers in Washington did not appreciate how security had deteriorated in Benghazi.

“I almost expected the attack to come,” said Wood, a member of the Utah National Guard.

“We were the last flag flying. It was a matter of time.”

Wood’s team left Libya in August after Lamb had refused to approve extending their assignment for a second time.

She said the State Department planned to turn over most basic protective duties to a Libyan guard force, part of a decade-long shift away from using U.S. Marines to protect embassies.

Lamb said the mix of State Department officers, Libyan guards and militiamen “could do the same function” as the U.S. military.

Republicans on the committee repeatedly criticized the Obama administration for initially describing the attack as a spontaneous outbreak of mob violence following an anti-American protest of an Internet video lampooning the Prophet Muhammad.

“This was never about a video,” yelled Rep. Trey Gowdy, R-S.C.

“This was never spontaneous, this was terror, and we have to ask why we were lied to.”

Speaking to reporters later Wednesday, White House spokesman Jay Carney said that administration officials, including U.N. Ambassador Susan Rice, had relied on preliminary information from U.S. intelligence agencies when they gave their initial assessments.

Carney would not comment directly on allegations that the administration had denied requests to improve security at the consulate in Benghazi.