BEIRUT -- A UN commission said yesterday it had asked a second time to question Syria's president about the assassination of a former Lebanese prime minister, turning up the pressure on Damascus after a former top government official said President Bashar Assad had issued a threat before the killing.
The commission's spokeswoman, Nasra Hassan, said it also wants to interview former Syrian vice president Abdul-Halim Khaddam ''as soon as possible."
Khaddam, a one-time stalwart of Syria's ruling party, said in a television interview last week that Assad had threatened the former prime minister, Rafik Hariri, several months before the truck-bomb assassination of Hariri on Feb. 14 in Beirut.
The allegations that Assad said he would ''crush whoever attempts to overturn our decision" to keep a pro-Syrian leader in Lebanon further deepened suspicions of Syrian involvement in the killing.
The UN commission asked to interview Assad in July but was refused. Hassan said the commission is ''waiting for a response from the Syrians." The Syrian government did not comment.
Syrian legislator Faysal Kalthoum said Damascus would reject the UN committee's request to interview Assad if it violates the dignity of the presidency.
''This request must not contradict the constitutional and legal rules surrounding the dignity of the presidency, the symbol of sovereignty and national dignity," he said. If it does, it will be rejected by all Syrians, he said.
The US ambassador to the UN, John Bolton, urged Syria to comply.
''We strongly support the commission's investigative efforts," Bolton said in a statement. ''We expect the government of Syria to comply with these requests fully and unconditionally as the Security Council resolutions require."
In the interview from Paris, where he is writing his memoirs, Khaddam became the first former senior member of the Syrian government to confirm allegations that Assad had threatened Hariri.
Hariri had been trying to block Syrian plans to extend the term of Lebanon's pro-Syrian president, Emile Lahoud.
The UN commission, whose mandate was recently renewed for six months by the UN Security Council, has reported Hariri told several witnesses after meeting Assad that the Syrian leader had threatened him for opposing a longer term.
Syrian officials have denied that the threat was made, and that they were involved in Hariri's killing.