The US state department has called on Tamil Tiger rebels to come up with a realistic position on power-sharing with the Sri Lankan Government so that peace talks can resume soon.
Formal talks broke down in April after the Tigers complained of bad faith on the part of the Sri Lankan Government.
The last round of peace talks took place in March
But a ceasefire continued with both sides saying they were still committed to finding a negotiated settlement.
The peace process has been in limbo for many months.
Washington reiterated its strong support for Sri Lanka's peace process, saying it is possible to end the two decade-long conflict if there is a constructive approach.
But the US state department criticised the Tamil Tiger rebels for continuing political assassinations and said it hoped the rebels would be realistic in response to government proposals for devolution of power.
These comments strengthen the hands of Norwegian mediators just as they arrive in Sri Lanka for a fresh round of meetings. It is hoped these will pave the way for a resumption of peace talks, perhaps as early as mid-October.
The peace process now hinges on proposals being formulated by the Tamil Tigers for an interim administration for the north-east of the island.
There has been huge speculation about what the rebel proposals might contain, but they will not be sent to the government until the end of the month.
Then it is expected both sides will arrange to meet in a foreign country, possibly Italy, to try and hammer out agreement on a rebel-dominated administration for areas of the island where Tamils live in large numbers.
All this is acquiring some urgency because without progress on the political front, $4.5bn construction aid pledged for Sri Lanka will not be forthcoming.