"This matter is totally out of the question on the Saudi-Syrian track," Hariri told the pan-Arab newspaper Al-Hayat in an interview published on Friday.

"Anyone who thinks that a government other than a national unity government can revive this country needs to think again." Hariri's government has been paralyzed for months by political tension over a UN-backed investigation into the 2005 bombing which killed his father, the powerful Sunni Muslim former premier Rafik Al-Hariri.

Diplomats expect members of the Shiite militant group Hezbollah, which has ministers in Saad Hariri's cabinet, to be named in draft indictments which are likely to be sent to the tribunal's pre-trial judge this month.

Hezbollah has denied any involvement in Hariri's killing. It has dismissed the five-year investigation into the bombing as politicized and urged Saad Hariri to denounce the UN-backed tribunal leading the probe - a demand he has so far resisted.

Analysts had said that if the tribunal does indict Hezbollah members, the group could, along with its Shiite and Christian allies in the cabinet, seek to bring down the government.

Hariri said the Saudi-Syrian initiative was "complete and awaiting implementation,” but insisted it was up to Hezbollah and its allies to make the first move.

"Any commitment on my side will not be implemented before the other party implements what it committed to," Al-Hayat quoted him as saying. "That is the basic principle of the Saudi-Syrian efforts." Prosecutor Daniel Bellemare is expected to send draft indictments to pre-trial judge Daniel Fransen soon. A tribunal spokesman has said details of the indictments would not be made public until Fransen approves them, a process which could take around two months.