The international community is condemning the assassination of Lebanese cabinet minister Pierre Gemayel.
The European Union rejected the attack Tuesday and called on all parties to avoid actions that would destabilize Lebanon.
U.S. Under Secretary of State Nicholas Burns said the murder was an act of terrorism and intimidation against Lebanon's elected government.
He added there is a pattern of violence and assassination in Lebanon's recent political history.
At the United Nations, U.S. Ambassador John Bolton said the killing highlights the need for the quick establishment of a special tribunal for Lebanon.
The proposed court would try suspects in last year's assassination of former Lebanese Prime Minister Rafik Hariri.
Syria's ambassador to the United Nations, Bashar al-Jaafari, said Syria had no role in what he called "horrible crimes" in Lebanon.
U.N. Secretary-General Kofi Annan praised Gemayel as someone who believed strongly in an independent, democratic and united Lebanon.
He added the killing came one day after the U.N. Security Council discussed the Lebanon tribunal.