WASHINGTON - The US on Tuesday welcomed Turkey's hard stance and decision to impose energy sanctions on Syria, a White House official told reporters, asserting that Syrian President Bashar al-Assad has been isolated.

"We very much welcome the strong stance that Turkey has taken and believe it sends a critical message to President Assad that he cannot crack down and oppress the aspirations of his people," White House deputy national security adviser Ben Rhodes said while traveling with President Barack Obama on Air Force One.

Turkey may consider terminating sale of electricity to neighboring Syria if tensions continue to escalate over the alleged Syrian crackdown on anti-government protests, Turkish Energy Minister Taner Yildiz said Tuesday.

Yildiz's statement came hours after Turkish President Abdullah Gul and Prime Minister Recep Tayyip Erdogan slammed the Syrian government for the weekend's attacks on the Turkish diplomatic missions in Syria following an Arab League (AL) decision to suspend Syria's membership in the organization.

"Turkey's comments today further point to the fact that President Assad is isolated," said Rhodes, urging him to step down.

"We see a growing tide of international opinion against President Assad. We welcome that and have sought to build upon that to apply pressure on the Assad regime," he said.

The Arab league decided on Saturday to suspend Syria's membership, to be effective on Wednesday, and then called on its members to withdraw ambassadors and impose sanctions on Damascus until it implements a peace plan brokered by the regional body, under which Syria would have stopped violence and withdrawn military vehicles from cities, released detainees and held dialogue with the opposition.

Washington on Tuesday urged the Arab League, in its meeting scheduled for Wednesday in Morocco, to send a "forceful message" to Syria.