The son of former Lebanese Prime Minister Rafik Hariri has called for his father's killers to stand trial in an international court.
Saad Hariri said the report should not harm Beirut's ties to Syria
"We are not seeking revenge, we are seeking justice," Saad Hariri said.
He was welcoming a UN report released late on Thursday which implicated Syrian officials and their Lebanese allies in the assassination.
Syria on Saturday repeated its long-standing denial of involvement in the February killing of Mr Hariri.
A Syrian spokesman said the report was based on preconceptions and the testimony of Syria's opponents.
Assistant Foreign Minister Ahmed Arnus said the report "puts Syria in the dock and vilifies it without evidence".
Syria offered a promise to co-operate further with the investigation, but the BBC's Ian Pannell in Damascus said it was unclear what that meant or whether it would satisfy Syria's many critics.
The US has urged swift action over the report ahead of a UN Security Council meeting on Tuesday that will discuss its findings.
US Secretary of State Condoleezza Rice said "there will have to be some way to ensure accountability for what has already been found here".
KEY UN FINDINGS
Assassins had considerable resources and capabilities
Evidence suggests both Syria and Lebanon were involved
Crime was prepared over several months
Hariri's movements and itineraries were monitored
Highly unlikely Syrian or Lebanese intelligence were not aware of assassination plot
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UK Foreign Secretary Jack Straw has said the Security council will consider imposing sanctions on Syria.
Speaking from his home in Jeddah, Saudi Arabia, Saad Hariri said his family accepted the conclusions reached by the UN investigation into his father's death.
"We call on the international community to uphold its support for the international commission into the assassination of Mr Hariri... and bring the perpetrators to justice in an international court," he said.
Saad Hariri said Beirut's ties with Damascus should not suffer as a result of the UN report.
"The implication of a few villains in the terrorist crime will not blur... our common history with the Syrian people who will remain for us... a dear, brotherly nation," he said.
He said he was "very encouraged" by UN Secretary General Kofi Annan's decision to extend the mandate of the investigation, led by German prosecutor Detlev Mehlis.
A coalition of anti-Syrian politicians led by Saad Hariri won a majority in Lebanon's elections earlier this year.
The victory followed the withdrawal of thousands of Syrian troops stationed in Lebanon as part of a peace deal ending years of civil war.
The Syrian withdrawal was the result of intense international pressure and massive anti-Syrian street protests in Lebanon, prompted by Mr Hariri's assassination on 14 February.