The United Nations called Lebanon's approval of a U.N. plan for an international tribunal for the suspected killers of former Prime Minister Rafik Hariri "an important step" in fulfilling its requirement to negotiate an agreement with the government.

U.N. spokesman Stephane Dujarric on Tuesday said Prime Minister Fuad Saniora had sent a letter to Secretary-General Kofi Annan informing the U.N. of the government's approval of the plan on Monday.

The secretary-general must now write a report to the U.N. Security Council about the government's decision, and the council must then decide whether to approve the final draft for the tribunal. If the council endorses the plan, it must then be approved by Lebanon's Cabinet again, signed by the president and approved by a vote in parliament.

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Saniora's government in under intense pressure, however, from Hezbollah and Lebanon's Shiite Muslims and final approval of the tribunal is far from certain.

Dujarric said "the secretary-general believes that the decision of the Lebanese Council of Ministers, approving the draft agreement and draft statute regarding the establishment of a tribunal of an international character, is an important step in fulfilling the Security Council's mandate in resolution 1664."

The resolution, adopted on March 29, asked Annan to negotiate an agreement with the government aimed at establishing a tribunal "of an international character based on the highest international standards of criminal justice" to assist Lebanon "in the search for the truth and in holding all those involved in this terrorist attack accountable."

Hariri was killed with 22 others in a suicide truck bombing in February 2005. The assassination sparked huge protests against Syria, which was widely seen as culpable. Syria denied involvement, but was forced to withdraw its troops from Lebanon, ending a 29-year presence.

Saniora, whose anti-Syrian majority dominates the Cabinet, convened a meeting Monday over the objections of pro-Syrian President Emile Lahoud and despite resignations of six pro-Syrian ministers, five of them Shiite Muslim who quit in a dispute with the prime minister.

Saniora is under additional pressure because Hezbollah, seen as the victor in the war against Israel this summer, has threatened to call mass protests unless it and its Shiite Muslim allies gain effective veto power in the Cabinet.

But Saniora indicated Monday that the tribunal was a top priority and he would press for its creation.

"We tell the criminals that we will not give up our rights, no matter what the difficulties and obstacles are," he said. "Our only aim is to achieve justice and only justice. Without it and without knowing the truth, the Lebanese will not rest and we cannot protect our democratic system and political freedom now and in the future."

The anti-Syrian camp in Lebanon has charged that Syria is behind the opposition to the tribunal because it seeks to avoid the prosecution of the Syrians implicated in Hariri's killing by a U.N. inquiry. Hezbollah officials have denied they are opposed to a U.N. tribunal.

Dujarric refused to comment on Lebanon's internal problems.

"We've accepted the letter at its face value and we're acting upon it and will move quickly to bring this to the Security Council," he said.

"After the review of the draft statute of the tribunal by the Security Council, the instruments, the framework of the tribunal, the papers will be sent again to the government of Lebanon. And the Lebanese authorities, at that point, will have an opportunity to review them, and follow the process required by their own laws," Dujarric said.

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