The Lebanese government approved today plans for a special court to try suspects in the 2005 assassination of former Prime Minister Rafik al-Hariri, official sources said.
The court is a major source of contention between the Western-backed government led by Prime Minister Fouad Siniora and the opposition, led by pro-Syrian Hezbollah.
Tension between the two groups escalated by Tuesday's assassination of Christian cabinet minister Pierre Gemayel.
Meanwhile the US ambassador to the United Nations warned the country's future is at stake in a battle between "democracy and terrorism" following the killing of Christian politician Pierre Gemayel. .
"The future of the Middle East, certainly the future of Lebanon may well be decided in the next several days," John Bolton told BBC radio.
"A successful re-emergence of democracy there is being directly challenged by the terrorist Hezbollah and those who support them, Syria, Iran and others."
Mr Bolton said it would be a "serious problem" if an investigation into Tuesday's assassination of Gemayel, a critic of Syria, found Damascus was involved.
"Then you have a further clear piece of evidence that Syria is not just a supporter of terrorism but is a state actor in a terrorist fashion," he said. "The United States has to take that into account when it decides whether and to what extent to deal with a country like that," he said, adding that the issue was not whether the United States would talk to Syria.
"The issue is whether Syria is going to listen," he said. Many in Lebanon have accused Syria of being behind the killing of Gemayel, but Damascus denies any hand in the attack, which it says damaged its own interests.
Diplomats say Syria now expects its enemies to use the killing to blacken its image and dash its hopes of a thaw in ties with the Europe and the United States. Damascus had been heartened by mounting calls for US President George W. Bush to talk to Syria and Iran, instead of punishing them, and to seek their help in stabilising Iraq.
British Prime Minister Tony Blair, who eased Syria's isolation earlier this month by sending a senior envoy for talks with President Bashar al-Assad on Iraq, the Israeli-Palestinian conflict and Lebanon, has avoided blaming Syria directly for Gemayel's killing.
Mr Bush also stopped just short of accusing Damascus of killing the industry minister, but voiced support for the Lebanese people's "efforts to defend their democracy against attempts by Syria, Iran and allies to foment instability and violence".
Mr Bolton said Lebanon had reached a "very dramatic point" in its history after the killing. A political crisis has been brewing in Lebanon for weeks with the pro-Syrian Hezbollah demanding more say in a government dominated by ministers from an anti-Damascus coalition.