The first divisions have appeared in the Geneva agreement on Syrian chemical disarmament as Russia dismissed calls for a swift UN resolution threatening punitive measures against Damascus.
The spat focused on the timing of a resolution under chapter 7 of the UN charter, which includes enforcement measures such as the possible use of military action to bolster a security council decision.
The Russian foreign minister, Sergei Lavrov, said calls for an immediate chapter 7 resolution showed a "lack of understanding" of Saturday's Geneva agreement with the US about the process of declaring, inspecting and dismantling Syria's chemical weapons.
Any resolution this week cannot include chapter 7, Lavrov insisted. "I am certain that despite the statements we are hearing from certain European capitals, the American side will firmly adhere to what was agreed," the Russian foreign minister said.
He was reacting to reports from a meeting in Paris between the US secretary of state, John Kerry, the French foreign minister, Laurent Fabius, and the UK foreign secretary, William Hague, who declared themselves united behind a tough UN resolution to put the Geneva agreement into practice.
"We want concrete, verifiable acts and all options must stay on the table if these are not done," Fabius said.
Hague added: "A resolution, in our view, should create a binding commitment for the regime to give up its chemical weapons within a specific time frame and to credibly, reliably and promptly place them under international control for destruction."
However, despite the robust rhetoric, neither Fabius nor Hague specifically called for a chapter 7 resolution.
The Geneva agreement leaves some room for debate on when such a resolution should be forthcoming. It calls for a security council resolution to be passed laying out a plan for Syrian disarmament which would include regular reviews of Syrian compliance.
It says in the event of non-compliance "the UN security council should impose measures under chapter 7 of the UN charter".
It does not say whether the original resolution laying out the plan should be under chapter 7, so that enforcement is automatic, or whether enforcement should be subject to a further vote.
"Russia did agree in Geneva that chapter 7 is mentioned specifically as the route for compliance if there is non-compliance or any use of chemical weapons by anyone in Syria," Kerry said in Paris. "In both of these circumstances, use of chemical weapons or non-compliance, you are already automatically into chapter 7 according to the agreement we came out of Geneva with."
Kerry added: "If the Assad regime believes this is not enforceable and we are not serious, they will play games. We're going to work hard to have a resolution that is as strong and forceful as possible.
"If Assad fails to comply with the terms of this framework, make no mistake, we are all agreed – and that includes Russia – that there will be consequences. Should diplomacy fail, the military option is still on the table.
"Nothing in what we've done is meant to offer any notion to Assad that there is some legitimacy to his process, that he has some extended period as a leader, so-called," Kerry said. "We make it clear that Assad has lost all legitimacy … to govern this country."
