US Secretary of State Hillary Clinton responds forcefully to intense questioniing on the September attacks on US diplomatic sites in Benghazi, Libya, during a Senate Foreign Relations Committee hearing on Capitol Hill in Washington January 23, 2013.[Photo/Agencies]

WASHINGTON - US Secretary of State Hillary Clinton on Wednesday in a congressional hearing took responsibility for the security failure in the attack on the US consulate in Benghazi, Libya. But she defended fiercely for the handling by the Obama administration on the attack's aftermath.

"As I have said many times since September 11, I take responsibility," Clinton said before the hearing held by the Senate Foreign Relations Committee. This is probably one of her last appearances in congress before she steps down as secretary of state.

"Nobody is more committed to getting this right. I am determined to leave the State Department and our country safer, stronger and more secure," she said.

The deadly September 11 attack in the eastern Libyan city of Benghazi last year killed US ambassador to Libya Christopher Stevens and three other Americans. The US State Department has been under harsh criticism for its inadequate protection of the US mission.

On December 18, the independent Accountability Review Board (ARB) released a review of the Benghazi attack, noting that "management deficiencies" at high levels of the State Department had contributed to the deadly outcome.

Following the report, four State Department officials were removed from their posts, including Eric Boswell, assistant secretary of state for diplomatic security.

Facing questionings from the senators, Clinton fiercely defended the administration against charges that it tried to cover up the truth surrounding the attack.

"With all due respect, the fact is, we had four dead Americans. Was it because of a protest or because of guys out for a walk one night and decided to go kill some Americans? What difference does it make?" Clinton responded angrily and pounded her fist on the table when repeatedly pressed by Republican Senator Ron Johnson.

"It is our job to figure out what happened and do everything we can to prevent it from ever happening again, senator," she said.  

Five days after the attack, US Ambassador to UN Susan Rice showed up in a number of American national television programs, characterizing the incident as one arising from a spontaneous protest over an American-made anti-Islam film. Her comments, which caused lots of controversies and were seen as misleading to the American people, cost her chance to become the next secretary of state.

For her defense, Clinton said that Rice's controversial statements were the result of a "typical" inter-agency process and many questions about the attack remained.

"We didn't know who the attackers were or what their motives were," she said. "The picture remains somewhat complicated."

Clinton turned emotional and even choked with tears in her eyes while talking about how she personally felt about the loss of four Americans in Benghazi.  

"This is not just a matter of policy. It's personal. I stood next to President Obama as the Marines carried those flag-draped caskets off the plane at Andrews (air force base)," Clinton told the senators. "I put my arms around the mothers and fathers, the sisters and brothers, the sons and daughters, and the wives left alone to raise their children."

Later in the afternoon, Clinton is expected to continue her hearing on the Benghazi attack before a House committee.