WASHINGTON (AFP) -- A first-ever blueprint for peace unveiled by Sri Lanka's Tamil Tiger rebels is "significant" and "comprehensive" but oversteps internationally endorsed guidelines for a settlement, a top U.S. official said Monday.

Deputy Secretary of State Richard Armitage said after meeting Sri Lankan Prime Minister Ranil Wickremesinghe here that an adapted version of the power-sharing plan could help progress towards ending a vicious civil war which has cost 60,000 lives.

The meeting laid the groundwork for Wickremesinghe's meeting with President George W. Bush on Wednesday, as peace broker Norway labors to set up new face to face talks between the Colombo government and Liberation Tigers of Tamil Eelam (LTTE).

The Tigers walked out of peace talks in April, accusing the Sri Lankan government of failing to deliver on promises in six previous rounds of negotiations.

Armitage said the Tigers' proposals unveiled last week were the first time he had seen such a "comprehensive delineation of the aspirations of the LTTE." "I think it is significant," he said.

But he cautioned that the blueprint "does go outside" declarations by Sri Lanka and the international community on guidelines for a final settlement after peace conferences in Oslo in 2002 and Tokyo earlier this year.

Those meetings, the second of which was boycotted by the Tigers, agreed the bedrock of a peace accord would be a federated Sri Lanka, established as a democracy based on human rights and territorial integrity of the entire island.

"It is significant and it may form the basis for a way forward for a process but I would say that we need to come back towards the boundaries envisioned by Oslo," Armitage said.

The LTTE plans seek to establish a de facto federal structure for embattled regions.

The Tigers are also asking for control over natural resources, including access to all marine and off-shore resources and control over the sea to a proposed Interim Self-Governing Authority (ISGA).

Armitage also said the blueprint was insufficient to Washington to remove the Tigers from a list of foreign terrorist organization -- a designation renewed last month.

"In order to be removed from the list, the LTTE must in word and deed eschew the use of terrorism, (and) violence against innocents as a political weapon," he said.

Wickremesinghe was Monday also meeting Deputy Defense Secretary Paul Wolfowitz ahead of meetings on Tuesday with Commerce Secretary Donald Evans and US Trade Representative Robert Zoellick. CAPTION: Richard Armitage (right) with Sri Lankan PM Wickremesinghe