European foreign ministers are to meet to discuss proposals from Britain and France to relax the EU arms embargo on Syria to enable more help to be given to rebel groups, Prime Minister David Cameron has said.
Mr Cameron said that he and French president Francois Hollande made the case at Friday's European Council summit in Brussels for the embargo to be changed so it no longer treated the opposition forces in the same way as the regime of dictator Bashar Assad.
Mr Cameron said it was "right to have that debate" before the embargo comes up for review at the EU in May.
He said: "It is worth reflecting that we are two years into this dreadful conflict. There are probably over 70,000 people who have lost their lives.
"We have to be frank that what the international community has done so far, of course, has helped in terms of humanitarian assistance - and I'm proud of the role Britain has played there - of course it has helped put pressure on the regime - and I'm proud of what we've done at the UN and here at the EU.
"But it hasn't overall worked in terms of stopping this conflict and achieving transition in Syria."
Mr Cameron welcomed Foreign Secretary William Hague's move last week to extend the "non-lethal" assistance which the UK can offer the Syrian opposition, to include equipment such as armoured vehicles.
He added: "Francois Hollande and I have agreed that it is also right to look at further changes in terms of the arms embargo, because at the moment it is basically still treating the Syrian regime in a pretty similar way to the Syrian opposition. This will be debated by foreign ministers."
Mr Cameron said that opponents of change argued that a political solution, and not a military solution, was needed in Syria.
But he said: "Of course people want a political solution. Of course I want a political solution. But this is not an either/or situation. I think we are more likely to see political progress if people can see that the Syrian opposition - which we have now recognised, that we are working with - is a credible and strengthening and growing force."