UNITED STATES President Barack Obama has "strongly" condemned the "outrageous" attack on the diplomatic facility in Benghazi, Libya, which left four Americans dead including Ambassador Chris Stevens.

On Tuesday night Stevens and three embassy staff were killed by Islamist gunmen who stormed the Benghazi consulate blaming America for a film they said insulted Prophet Muhammad.

Obama said the victims "exemplified America's commitment to freedom, justice and partnership with nations and people around the globe and stand in stark contrast to those who callously took their lives".

Obama said "all necessary resources" would be sent to support the security of the other personnel in Libya.

"While the United States rejects efforts to denigrate the religious beliefs of others we must all unequivocally oppose the kind of senseless violence that took the lives of these public servants," Obama stated.

United States Secretary of State Hillary Rodham Clinton, yesterday said all the Americans who lost their lives in the attack "made the ultimate sacrifice".

"We condemn this vicious and violent attack that took their lives, which they committed to helping the Libyan people reach for a better future," Clinton said.

The United Nations Security Council yesterday "underlined the need to bring perpetrators of these acts to justice".

"The members of the Security Council reaffirmed that such acts are unjustifiable regardless of their motivations whenever and by whomever committed," a release from the Security Council stated yesterday.

Stevens, a 21-year veteran of the Foreign Service, was sworn in as Ambassador to Libya a few months ago.

"As the conflict in Libya unfolded, Chris was one of the first Americans on the ground in Benghazi. He risked his own life to lend the Libyan people a helping hand to build the foundation for a new, free nation," a release from Clinton stated yesterday.

"He spent every day since helping to finish the work he started. Chris was committed to advancing America's values and interests, even what meant putting himself in danger," Clinton stated.

Also killed in Tuesday's attack was Foreign Service Information Management Officer Sean Smith.

Smith was a husband and a father of two who joined the Department ten years ago.

"Like Chris he was one of our best," Clinton stated.

—Joel Julien