David Cameron insisted today that he remained hopeful of securing a United Nations Security Council resolution against Syria despite the G8 summit failing to endorse one.
The Prime Minister blamed the willingness of some countries, in contrast with the UK, to give the regime more time to end repression for an apparent weakening of the position.
Moscow was reported to be behind a watering down of the final communique, which promised only that the G8 would "consider further measures".
Earlier drafts explicitly indicated that a UN Security Council resolution could be sought if the regime did not end human rights violations.
Britain, France, Germany and Portugal circulated a draft resolution earlier this week condemning the "systematic violation of human rights" by President Bashar Assad's government.
Speaking as at least eight more protesters were killed under fire from security forces, the Prime Minister said he believed Assad had clearly chosen not to take the path of reform.
"The British Government is very clear: what's happened is unacceptable, the outrages committed by the regime, the amount of people who have been shot on streets, this all adds up to a very serious indictment of that regime," he told a post-summit press conference.
"That is why we have been at the vanguard of pushing for travel bans and asset freezes at the European level and also pushing for a UN Security Council (resolution)."
Asked why the language of the communique appeared to be so weak, he said: "The difficulty is that there is not the same unity in the Arab world as there was over Libya for action and I think there also is a sense from some countries, particularly those who have dealt with Syria for a long time, that there is still a fork in the road where Assad could choose reform rather than repression.
"In my view, he has chosen repression and it is pretty clear that's the case but I think that is why the language is as you say it is.
"Although do not underestimate the fact that the EU has taken action and I think there are prospects for Security Council resolutions as well."