U.S. Sen. Kelly Ayotte joined with three of her Republican colleagues Wednesday to call on the Obama administration to answer questions about its handling of the Sept. 11 terrorist attack in Benghazi, Libya.

Ayotte signed a letter with a list of inquiries along with Sens. John McCain of Arizona, Lindsey Graham of South Carolina and Ron Johnson of Wisconsin. In a statement, the three said that "failure to provide answers raises questions about whether the administration is deliberately stonewalling Congress and the American people."

The letter says, "The American people and their representatives in Congress need to understand what you knew about the Benghazi terrorist attack and when you knew it. We also have a right to know what steps you and your administration took - or failed to take - before, during, and after the terrorist attack to protect American lives."

The senators wrote that they sent a letter to senior intelligence officials in the administration on Oct. 9, but, "More than three weeks have passed, and we still have not received a response.

"To make matters worse, since that original letter, we sent several subsequent letters to you or to your senior administration officials asking a number of questions, and we have failed to receive a single letter in response."

The senators ask:

-- "Within 48 hours of the attack, was there credible information and reporting to suggest that the assault on our Consulate and other U.S. facilities in Benghazi should be characterized as a terrorist attack?"

-- "At what time did intelligence community agencies or elements first assess that the events in Benghazi were a terrorist attack?

-- "What information did the intelligence community provide to senior policy makers that led some of them to draw the conclusion as late as five days after the attack in Benghazi that it was the result of a spontaneous demonstration, not a terrorist act?

-- "Was there no credible evidence at that late date that was compelling enough for the intelligence community and the senior policy makers to draw a conclusion with at least moderate confidence that the attack in Benghazi was a terrorist act?"