WASHINGTON — Executing a global squeeze play, the United States and its European allies on Thursday demanded an end to four decades of family dictatorship in Syria and underscored the tough talk with new sanctions on President Bashar Assad's government.
The unified stance isolates Assad further as he presses a military campaign against major demonstrations. But the diplomacy left many questions unanswered, including how the demand for Assad's ouster can be backed up in the absence of any appetite for military intervention, and who inside the Syrian government or among the country's fragmented opposition might take his place.
Much of Syria was quiet Thursday, although activists reported intense shooting around noon in the flashpoint city of Latakia.
Rights groups say Assad's forces have killed nearly 2,000 people since mid March. The military assault on civilians has escalated since Ramadan began, with security forces killing hundreds and detaining thousands.
In Thursday's coordinated statements, President Barack Obama and the leaders of Britain, France, Germany, Canada and the European Union called for Assad to resign, saying his repression of demonstrations inspired by this spring's Arab uprisings made him unfit to lead.
In a statement released by the White House, Obama said Assad had lost all credibility as a leader and had to go.
"His calls for dialogue and reform have rung hollow while he is imprisoning, torturing and slaughtering his own people," Obama said. "We have consistently said that President Assad must lead a democratic transition or get out of the way. He has not led. For the sake of the Syrian people, the time has come for President Assad to step aside."
British Prime Minister David Cameron, French President Nicolas Sarkozy and German Chancellor Angela Merkel issued a joint statement saying that Assad should "leave power in the greater interests of Syria and the unity of his people."
Obama said Assad was wrong to think he could silence the voices of his people with repressive tactics similar to the ones his father, Hafez Assad, used to crush opponents in the 1980s. Obama signed an executive order that gives his administration authority to impose sweeping new sanctions on Syria intended to further isolate Assad.
The order immediately bans the import into the United States of any Syrian petroleum or petroleum products. Syrian crude oil exports go mostly to European countries such as Germany, Italy and France, according to the U.S. Energy Information Agency.
Obama's order also denies Syria access to the U.S. financial system, freezing all Syrian government assets that are subject to American jurisdiction.
Secretary of State Hillary Rodham Clinton and Obama stressed that no one would impose transition in Syria.
"We understand the strong desire of the Syrian people that no foreign country should intervene in their struggle, and we respect their wishes," Clinton said at the State Department. "At the same time, we will do our part to support their aspirations for a Syria that is democratic, just and inclusive, and we will stand up for their universal rights and dignity by pressuring the regime and Assad personally."