Western and Arab powers agreed with Syrian opposition leaders Tuesday that President Bashar al-Assad should be excluded from any future government, but urged the rebels to take part in a peace conference in Geneva, Hurriyet Daily News reported.
British Foreign Secretary William Hague said after a meeting in London that the rebels had to overcome their differences and commit themselves to the talks in the Swiss city that are due to take place in late November.
But a defiant Assad said he was willing to run for re-election in 2014, a move further likely to anger a key rebel group that has so far refused to take part in the Geneva 2 conference if regime figures are present.
Hague told a press conference after the meeting of the so-called Friends of Syria that they had agreed a "number of important steps" during a meeting with Ahmad Jarba, the head of the Syrian National Coalition.
"We are as clear as he is that Assad has no role in a peaceful and democratic Syria," Hague said.
US Secretary of State John Kerry urged the world to help find a negotiated settlement for Syria, adding that the country itself could disintegrate if more is not done.
"The only alternative to a negotiated settlement is continued if not increased killing," Kerry told reporters.
"We believe that the state of war will simply lead to the implosion of the state of Syria." The London talks grouped Britain, Egypt, France, Germany, Italy, Jordan, Qatar, Saudi Arabia, Turkey and the United Arab Emirates and the United States, together with Syrian opposition leaders.
The Syrian National Council, a key member of Jarba's Syrian National Coalition, has already said it opposes the Geneva conference and threatened to quit the umbrella opposition group if Assad's regime takes part.
Hague said that Jarba had to "carry others with him" ahead of a meeting of leading rebel groups in early November, when they will decide whether or not to take part in the Geneva meeting.
He added: "Despite the enormous challenges faced by the Syrian opposition, we urged the National Coalition to commit itself fully to the Geneva 2 process, and lead and form the heart of any opposition delegation." In a communique after the meeting, the Friends of Syria agreed that when a transitional government was established "Assad and his close associates with blood on their hands will have no role in Syria.
"There must be accountability for acts committed during the present conflict." Notably absent from London's meeting is key Syria ally Russia, which has dismissed such gatherings in the past, saying they do not represent all Syrian people.
Hague also warned of the need to bolster moderate forces in Syria, where an estimated 115,000 people have been killed since March 2011 and several million more made homeless.
"The longer this conflict goes on, the more sectarian it becomes and the more extremists are able to take hold, that is why we are making this renewed effort to get the Geneva peace process going," he said.
The United States and Russia have been trying to organise the Geneva conference on the heels of the deal they reached for the destruction of Syria's chemical weapons in the wake of a deadly poison gas attack in August widely blamed on Damascus.
But Assad dealt an early blow to peace hopes, saying in an interview Monday that the factors are not in place for the conference to succeed.
"No time has been set, and the factors are not yet in place if we want (Geneva 2) to succeed," Assad told Lebanon-based pan-Arab satellite channel Al-Mayadeen, adding that there was no guarantee about "which forces are taking part." Assad also gave no hint of releasing his grip on power.
"Personally, I don't see any reason why I shouldn't run in the next election," Assad declared.
Hague earlier said that Iran - Damascus's main regional ally - could also play a role in the Geneva talks if it backed the need for a transitional government in Syria.