Hillary Clinton Wells Up As During Benghazi Attack Testimony (PICTURES)

The memory of the flag-draped caskets of the Americans killed in the attack on the US consulate in Libya caused an emotional Hillary Clinton to well up as she face a grilling from the Senate foreign policy panel.

The secretary of state gave congressional testimony on her role during the assault on the US diplomatic mission in Benghazi, where Ambassador Chris Stevens and three other Americans were killed in an attack on the consulate, as protests raged over the controversial "Innocence of Muslims" film.

Secretary of State Hillary Rodham pounds her fist as she testifies on Capitol Hill

Clinton insisted she took full responsibility for what happened during the attack, which took place on September 11.

Her voice breaking at times, Clinton said: "I stood next to President Obama as the Marines carried those flag-draped caskets off the plane at Andrews.

"I put my arms around the mothers and fathers, sisters and brothers, sons and daughters," she said.

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

Clinton gives a passionate testimony to the Senate Foreign Relations Committee hearing on the deadly September attack

Her testimony focused not only on the attack but the growing threat from extremists in northern Africa, pointing out that Libya was not an isolated incident.

In what will probably be one of her last high-profile appearances on Capitol Hill before she leaves the post, said she had covered nearly 1 million miles and 112 countries in four years

"My faith in our country and our future is stronger than ever. Every time that blue and white airplane carrying the words "United States of America" touches down in some far-off capital, I feel again the honor it is to represent the world's indispensable nation.

"And I am confident that, with your help, we will continue to keep the United States safe, strong, and exceptional."

But she faced damning accusation from the Senate Foreign Relations Committee, with Republican and former presidential candidate John McCain calling it "a cover-up from the beginning".

More criticism came from Republicans like Florida's Marco Rubio and Kentucky's Rand Paul, who said Clinton "should have been fired for letting "the worst tragedy since 9/11" happen on her watch.

Libyans hold placards as they march to express their sympathy for the US ambassador, Chris Stevens and other Americans killed

Republican Ron Johnson also criticised how Clinton had intially reported that the attack had been mounted in reaction to the anti-Islam YouTube video, and not, as was later discovered, a pre-planned terror attack.

Clinton said: "With all due respect, the fact is we had four dead Americans. Was it because of a protest or was it because of guys out for a walk last night who decided to kill some Americans?

"What difference at this point does it make? It is our job to figure out what happened and do everything we can to prevent it from ever happening again, Senator.

"Honestly, I will do my best to answer your questions about this, but the fact is people were trying their best in real time to get to the best information.

"Give me a break, Senator Johnson. This whole thing is the biggest fairy tale I've ever seen."