"We look forward to supporting the National Coalition as it charts a course toward the end of Assad's bloody rule and the start of the peaceful, just, democratic future that all the people of Syria deserve," State Department deputy spokesman Mark Toner said in a statement.
Activist preacher Moaz al-Khatib was elected as the first leader of a new Syrian opposition umbrella group that hopes to win international recognition and prepare for a post-Assad Syria, in a poll counted before reporters on Sunday.
Veteran opposition figure Riad Seif, who proposed the U.S.-backed initiative to set up an umbrella group of opposition groups inside and outside Syria, was elected as deputy president along with Suhair al-Atassi, a well-known female activist.
The election of al-Khatib was a surprise to observers, as he recently rarely spoke to the media and did not associate himself with the opposition.
Opposition figures had struggled for days in Doha to find unity, under heavy pressure from U.S. diplomats and officials from Qatar, which has bankrolled much Syrian opposition activity since an uprising began last year.
Khatib, a former imam at the famous Umayyad mosque in Damascus, was imprisoned several times for criticising Assad's rule before he left Syria for Cairo this year. Delegates said he had been the only candidate for the post of president.
In the capital of Qatar, Doha, representatives of various associations and groups making up the Syrian opposition signed an agreement forming a united opposition group to be called the National Coalition (NC), which will represent the interests of all opponents of the regime of Syrian President Bashar al-Assad.
The forum was not attended by a significant number of the Syrian opposition leaders who refused to participate in the newly created structure.
One of the organizations refusing to participate is called the "Movement for a Peaceful Settlement" in Syria. Its leader, Fateh al-Jamus spoke to the "Voice of Russia" about the reasons for not participating in the conference and expressed his views on the initiatives.
He stated: "We are holding back our opinion of the external opposition. Any action taken by an organization outside the borders of our country can not make a difference. This activity leads to a dependence on foreign players from a geopolitical and a financial point of view. The work of a true opposition must be implemented from within the country. As for external conferences, they have shown that they only contribute to strife amidst the opposition, and do not unite it. Such conferences cause a distorted view of the regime”.
According to Whitehall sources, British special forces are helping to train rebel assassination squads to target President Assad. Troops from the SAS, SBS and Paras from the Special Reconnaisance Regiment are in Syria helping show insurgents how to use new weapons and explosives.
The Prime Minister is preparing to use the RAF to enforce no-fly zones across President Assad’s trouble-torn country in a bid to stop mass slaughter.
At this week’s National Security Council meeting in Downing Street Syria will be number one on the agenda.
Cameron and newly re-elected US President Barack Obama are also considering military action and officially arming rebels.
The first stage of the plan involves a no-fly zone that will be patrolled by British, US and French forces. Safe havens will be set up in Syria, Turkey and Jordan.
Syrian opposition groups have signed an initial agreement to form a new coalition of forces fighting to end the rule of President Bashar al-Assad, a Syrian delegate at talks in Doha said on Sunday.
"An initial deal has been signed. The evening session will be for electing the president of the body and his deputy," Ali Sadreddine al-Bayanouni, a Muslim Brotherhood delegate at the talks, told reporters.
The new body, made up of groups inside and outside Syria, would be called the National Coalition for Opposition Forces and the Syrian Revolution, he added.
Syrian opposition groups are set to resume talks in Qatar to try to form a united body in the fight against President Bashar al-Assad.
Delegates were quoted as saying that main points had already been agreed.
The fractious opposition has been under pressure from the US and other backers in the region to clinch a deal.
However, the Syrian National Council - which is based outside the country - is concerned it may be sidelined by the new opposition body.
The proposed unified group, tentatively called the Syrian National Initiative, is intended to merge disparate military and political groups to form a credible alternative to Mr Assad's government.
Armed extremists continue to carry out terrorist sallies in Damascus.
On Saturday a car bomb went off, injuring dozens of people in the southern part of the city. In the Christian sector of the Syrian capital militants fired homemade rockets at residential homes, leaving several people in grave condition.
Shells exploded in an elite quarter of downtown Damascus, damaging several buildings.
Meanwhile, the Syrian military continue an operation against terrorists in the capital. At least 80 mercenaries were wiped out in the last 24 hours.
Voice of Russia, AFP, Reuters, RIA, dailystar, TASS, BBC