Syria envoy Kofi Annan will appear before the United Nations General Assembly and Security Council later amid increasing concern his plan for peace in the country is doomed.
There is broad agreement in New York that his current efforts to end the bloodshed and start a political process are not working and reports from monitors on the ground in Syria confirm President Bashar al Assad's regime shows no sign of wanting to comply.
The US, the UK, France and others have warned repeatedly that if the situation remains as it is, Syria risks plunging into a full-blown civil war that would destabilise the entire region.
But despite these concerns, exacerbated by events like the recent massacre in Houla, there is also a consensus Mr Annan's plan remains the only realistic hope, however precarious, of preventing such a thing happening.
UK ambassador to the UN Sir Mark Lyall Grant said: "The Annan plan is on life support, but it is not dead."
To help revive it, senior diplomats familiar with the Annan mission say he is considering setting up a contact group that would help to negotiate a political transition in Syria.
Political transition, including an agreed timeline to hold elections choosing President Assad's successor as well as a new constitution, is the key plank of Mr Annan's strategy.
The contact group would include the permanent members of the Security Council - the UK, France, US, China and Russia - as well as Saudi Arabia, Turkey and possibly even Iran.
Diplomats suggested that in return for the use of Moscow's diplomatic muscle, Russia might receive guarantees relating to its interests in Syria, which include a naval base.
UN sources have said this approach may be one of the only multilateral options left, even though it is unclear whether Russia would agree to take part.
Moscow has so far refused to back any further Security Council resolutions against Syria and says it will continue to do so, paralysing any efforts to increase pressure on the Syrian government through sanctions or the threat of military intervention.
There is also a reluctance to send more UN monitors to Syria or arm them, with UN officials fearing that such a move would increase the already considerable threat to their safety.
Council diplomats recognise that time is running out.
Senior officials have stressed that "immense effort" is being expended trying to gain consensus among the permanent members of the Security Council on how to make the Annan plan work.
What happens next, they say, hinges on the envoy's ability to convince them that there is a way forward for his strategy in the face of mounting cynicism - one influential diplomat told Sky News Online that the Annan plan is "a mess".
"That may be true," said another, "but it is the only mess we've got."