The official, who requested anonymity, said that Bush could levy the punitive measures on Damascus "as early as Tuesday" but that the precise date of the announcement could change.

Deputy Secretary of State Richard Armitage told the US-sponsored Arabic television channel al-Hurra in an interview last week that new sanctions on Syria were "inevitable" and would come "probably this month."

In late April, the White House said that implementation of sanctions was imminent, based on Syria's ties to terrorists; tacit support for insurgents in Iraq; and efforts to obtain weapons of mass destruction.