A top general close to Syria's President Bashar al-Assad has defected, in a move hailed by Washington and the Syrian opposition as a major blow to Damascus, a source close to the regime told AFP on Friday.

"General Manaf Tlass defected three days ago," the source close to the Syrian government said on condition of anonymity.

Tlass, the highest-ranking military officer to have abandoned the Assad regime, was on his way to Paris to join his wife and sister, Nahed Ojjeh, widow of Saudi millionaire arms dealer Akram Ojjeh, said the source.

France, which on Friday hosted an international meeting on the almost 16-month-old conflict in Syria, confirmed the report.

"A senior official from the Syrian regime, a commander in the Republican Guard, has defected and is headed for Paris," Foreign Minister Laurent Fabius told a news conference, without explicitly naming Tlass.

Tlass, who is in his late 40s, was a member of the inner circle in Syria, and a childhood friend of Assad.

A general in the elite Republican Guard charged with protecting the regime, he is the son of former defence minister Mustafa Tlass, a close friend of Assad's late father and predecessor, Hafez.

In Washington, the Pentagon said the defection signalled cracks in Assad's inner circle.

"We welcome this defection and we believe it is significant," spokesman Captain John Kirby said. "He's a senior official in the Syrian army and a former friend of Assad, so we do believe this defection shouldn't be taken lightly."

The United States hopes "others would follow his example," Kirby said, cautioning that Assad has "loyalists still around him and certainly the vast majority of the Syrian military is still following his orders."

But the defection was "a crack in that inner circle."

US Secretary of State Hillary Clinton, in Paris for a "Friends of Syria" meeting, said Damascus regime officials and officers were "starting to vote with their feet."

"To those soldiers who are still supporting the regime, the Syrian people will remember the choices you made in the coming days and so will the world," she told journalists.

"It is time to abandon the dictator, embrace your countrymen and women and get on the right side of history."

So far there has been no official reaction from Damascus to the defection.

-- SNC wants to cooperate with Tlass --

In Paris, the opposition Syrian National Council head, Abdel Basset Sayda, called the defection a major blow to Assad's regime and said the SNC wanted to work with him.

"This is a major blow to the Assad regime," he said. "We cannot comment where he is. We are going to seek some cooperation with him. We call for other defections."

Meanwhile, in an unauthenticated and undated email received by AFP on Friday and apparently signed by Tlass, the general himself appears to call on his comrades to follow his lead.

"I did not joined the armed forces to see this army harm its own people, whithout giving systematically a chance to political solutions," the email in English and Arabic reads.

"Thus, because I was in complete opposition with the unjustifed violence and crimes committed by Assad's regime in the past months, I was progressively dismissed from my place of duty in the armed forces.

"Today, I call for all my comrades in armed forces, whatever their rank in the hierarchy, who are dragged into this fight against their Syrian fellows and against their own ideals, to end supporting this regime."

The Sunni official's family is originally from the rebel-held town of Rastan in the central province of Homs, that is currently besieged and being bombarded by government forces.

Tlass was sidelined by the regime more than a year ago after being deemed unreliable.

His defection comes two weeks after a colonel in the privileged Syrian air force won political asylum after landing his MiG-21 fighter in neighbouring Jordan.

According to the source with close ties to Damascus, Tlass undertook several unsuccessful reconciliation missions between regime loyalists and rebels in Rastan and the southern province of Daraa.

Months later he gave up his military uniform and opted for civilian clothing. He set up residence in Damascus, where he let his beard and hair grow long.

Another source in Damascus told AFP that Tlass's relations with the authorities became irreconcilable after the regime's fierce assault on the Homs district of Baba Amr in February that cost hundreds of lives.

Tlass reportedly refused to lead the unit tasked with reclaiming the former rebel stronghold, and Assad subsequently told him to stay at home.

The source said Tlass was furious when Assad refused to promote him from brigadier general to divisional general or commander, when the yearly promotion list was published on July 1.

Sources close to Tlass say his family is now in Dubai, including his businessman brother Firas. When the uprising against Assad's regime broke out in March last year, the businessman wrote a blog post supporting the uprising.

Tlass's cousin Abdel Razzak defected from the military several months ago, and heads the rebel Free Syrian Army's Farouk Battalion in Homs.

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