BRUSSELS: British Prime Minister David Cameron said on Friday the Syrian government must be held accountable for what he called crimes against its citizens during the year-long revolt against President Bashar Assad.

"We need to start collecting the evidence now so that one day, no matter how long it takes, there will be a day of reckoning for this dreadful regime," Cameron told reporters as he arrived for the second day of a summit of EU leaders in Brussels.

"What I think matters is building the evidence and the picture so we hold this criminal regime to account and to make sure that it is held to account for its crimes that it is committing against its people."