— WASHINGTON (AP) — The U.S. military did not quickly intervene during the attack on the U.S. Consulate in Libya last month because military leaders did not have adequate intelligence information and felt they should not put American forces at risk, Defense Secretary Leon Panetta said Thursday.

In his most extensive comments to date on the unfolding controversy surrounding the attack in Benghazi, Panetta said U.S. forces were on heightened alert because of the anniversary of 9/11 and prepared to respond. But, he said, the attack happened over a few hours and was over before the U.S. had the chance to know what was really happening.

"(The) basic principle is that you don't deploy forces into harm's way without knowing what's going on; without having some real-time information about what's taking place," Panetta told Pentagon reporters. "And as a result of not having that kind of information, the commander who was on the ground in that area,- Gen. Ham, Gen. Dempsey and I felt very strongly that we could not put forces at risk in that situation."

Panetta was referring to Gen. Carter Ham, the head of U.S. Africa Command, and Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff.

In a letter to Obama Thursday, House Speaker John Boehner questioned if the White House considered military options during or immediately after the attack, and he questioned what the president knew about the security threats in the country. He said that the national debate over the incident shows that Americans are concerned and frustrated about the administration's response to the attack.

"Can you explain what options were presented to you or your staff, and why it appears assets were not allowed to be pre-positioned, let alone utilized? If these reports are accurate, the artificial constraint on the range of options at your disposal would be deeply troubling," Boehner wrote.

U.S. Ambassador Chris Stevens and three other Americans were killed in the attack, which has become a heated campaign issue less than two weeks before the election. Republicans have criticized the Obama administration's failure to more quickly acknowledge that intelligence suggested very early on that it was a planned terrorist attack, rather than spontaneous violence erupting out of protests over an anti-Muslim film.

House and Senate Republicans as well as presidential candidate Mitt Romney, have criticized President Barack Obama and administration officials over the response to the attack and whether officials failed to provide enough security at the consulate.

And there have been ongoing questions about whether there should have been additional military forces sent to the consulate immediately after it became clear that the Americans were under attack.

During a news conference, Panetta lamented the "Monday morning quarterbacking" that has been going on about how the U.S. handled the attack. And Dempsey, sitting alongside Panetta, bristled at questions about what the military did or did not do in the aftermath.

Noting that there are reviews already going on, Dempsey added, "It's not helpful, in my view, to provide partial answers. I can tell you, however, sitting here today, that I feel confident that our forces were alert and responsive to what was a very fluid situation."

The Senate Select Committee on Intelligence has announced it will hold a closed hearing Nov. 15 into the circumstances surrounding the terrorist attack, including the intelligence and security situation there, and additional hearings will follow.