The US Senate passed a resolution last night condemning the attacks on the US Consulate in Libya and said they were confident the perpetrators would be brought to justice.
The resolution, proposed by Senator John Kerry and Richard Lugar, said:
"The deaths of Ambassador Stevens and his team are heartbreaking. The violence in Cairo and Benghazi is unacceptable and unjustifiable.
"The stupidity of one filmmaker, no matter how offensive, is not now, and never, a rationale for violence.
"President Obama has appropriately committed the United States to bringing the perpetrators of this attack to justice, and I am confident that this is precisely what the United States Government will do."
Barack Obama has said that the US will see justice over the attack on its consulate in Libya.
Speaking in Las Vegas on the campaign trail tonight President Obama told the crowds that; "we will bring their killers to justice."
US officials have told the AP news agency that the Pentagon is moving two warships towards the Libyan coast.
A US official said the deadly assault on the country's consulate in Benghazi was "clearly a complex attack" but refused to speculate on who carried it out, Reuters has reported.
The official also said it was too early to say whether the attackers had links to people or groups outside of Libya.
The US has evacuated all personnel from its Benghazi consulate following yesterday's assault that killed the ambassador and three embassy staff, Reuters have reported.
An official said the workers have been relocated to the American Embassy in Tripoli, which has itself been reduced to emergency staffing levels to accommodate the arrivals.
The US has begun investigating whether the assault on a US consulate in Libya, in which the ambassador and three staff were killed, was a planned terrorist strike to mark 9/11.
Yesterday's assault on the US mission in Benghazi came as America observed a day of remembrance for September 11 victims on the 11th anniversary of the plane attacks in New York and Washington.
The United Nations has strongly condemned the assault that killed the US ambassador to Libya and three embassy staff.
The attack yesterday on the consulate in Benghazi and a safe house refuge was carried out by Islamist gunmen blaming America for a film they said insulted Prophet Mohammad.
– UN Secretary-General Ban Ki-moon
The United Nations rejects defamation of religion in all forms. At the same time, nothing justifies the brutal violence which occurred in Benghazi.
Ban said Libyan employees of the US consulate also had been killed but he did not specify how many. Libya's Deputy UN Ambassador Ibrahim Dabbashi said "less than 10 victims" were Libyan security force members.
Prime Minister David Cameron said he has sent a message to President Obama to say the "thoughts of people across Britain are with the families, colleagues and friends of the Americans killed in Benghazi, including Ambassador Chris Stevens."
Mr Cameron added:
This senseless attack ended the lives of people who had worked selflessly alongside Libyans during their darkest days.
We look to the new Libyan authorities to do all in their power, as they have pledged to do, to bring the killers to justice. Britain stands ready to assist Libya and the United States in that task.
Above all, we will honour the memory of these dedicated people by continuing their work to help Libyans build a secure and free country.
US Secretary of State Hillary Clinton, who appointed Chris Stevens as the envoy to the rebel opposition in Libya, said the late ambassador "risked his life to stop a tyrant then gave his life trying to help build a better Libya."
Mr Stevens and three of his embassy staff were killed in a mob attack on the US consulate in Benghazi yesterday that has received international condemnation.
NATO Secretary General Anders Fogh Rasmussen has added his voice to the international condemnation of the attack on the US consulate in Benghazi, Libya.
– Anders Fogh Rasmussen
I strongly condemn the attack on the US mission in Benghazi which led to the tragic loss of four Americans, including the Ambassador. Such violence can never be justified.
I offer my deepest condolences to the families and loved ones of those who lost their lives and my thoughts are with those who are injured.
I welcome the Libyan President’s condemnation and condolences and his pledge of his government’s full cooperation. It is important that the new Libya continues to move towards a peaceful, secure and democratic future.