The United States and the European Union (EU) Thursday called on Syrian President Bashar al-Assad to step down from power.
President Assad's calls for dialogue and reform "have rung hollow while he is imprisoning, torturing, and slaughtering his own people", U.S. President Barack Obama said in a statement.
"We have consistently said that President Assad must lead a democratic transition or get out of the way," the statement said.
"The future of Syria must be determined by its people," Obama said. "But President Bashar al-Assad is standing in their way."
"For the sake of the Syrian people, the time has come for President Assad to step aside."
Leaders of France, Germany, the United Kingdom, and the European Union echoed Obama's stance.
"Our three countries believe that President Assad, who is resorting to brutal military force against his own people and who is responsible for the situation, has lost all legitimacy and can no longer claim to lead the country," British Prime Minister David Cameron, French President Nicolas Sarkozy and German Chancellor Angela Merkel said in a joint statement.
"The EU notes the complete loss of Bashar al-Assad's legitimacy in the eyes of the Syrian people and the necessity for him to step aside," the EU foreign policy chief Catherine Ashton said in a statement.
"The EU condemns in the strongest terms the brutal campaign Bashar al-Assad and his regime are waging against their own people," Ashton said.
The EU has repeatedly urged that the violence against civilians in Syria must be stopped, detained protesters released, free access by international humanitarian and human rights organizations and media allowed, and a genuine and inclusive national dialogue launched.
"The Syrian leadership, however, has remained defiant to calls from the EU," Ashton said. "This shows that the Syrian regime is unwilling to change."
Obama said in the White House statement that his Administration has announced unprecedented sanctions against Syria.
He said he had signed a new Executive Order to freeze of all assets Syrian government subject to U.S. jurisdiction, to prohibite U.S. persons from engaging in any transaction involving the Government of Syria, to ban U.S. imports of Syrian-origin petroleum or petroleum products, to prohibit U.S. persons from having any dealings in or related to Syria’s petroleum or petroleum products, to prohibit U.S. persons from operating or investing in Syria.
Quickly following the Obama'sstatement, the U.S. Treasury announced that it barred trade with five Syrian oil and gas companies, including General Petroleum Corporation, Syrian Company For Oil Transport, Syrian Gas Company, Syrian Petroleum Company and Sytrol.
"We have been reaching out to our partners in the region and calling for a Special Session of the UN Human Rights Council on Syria," Ashton said in the EU statement.
"The addition of further names to the list of those targeted by the EU restrictive measures is under preparation," Ashton said. "The EU is moving ahead with discussing further restrictive measures that will broaden its sanctions against the Syrian regime."
The four European members of the Security Council -- Britain, France, Germany and Portugal -- announced Thursday that they would begin working on a Security Council sanctions resolution on Syria.