The defection of a Syrian general who is a personal friend of President Bashar al-Assad gave a huge boost to anti-government rebels as Western and Arab states met them in Paris on Friday to help prise Assad from power. 

Manaf Tlas, a brigade commander in the Republican Guard who attended military college with Assad and fled to Turkey this week, was on his way to Paris, where his father, Assad's father's defense minister, has also taken up residence, a close family friend told Reuters. 

There was no immediate sign that Tlas would throw in his lot with the rebels and an opposition source said he had no plans to attend Friday's meeting. 

While the lightly armed rebels are no match for Syria's large and well-equipped army, their hope lies in eroding loyalty and conviction within Assad's establishment to the point where it loses its hold on power. 

Government forces pushed into the rebel-held northern town of Khan Sheikhoun on Thursday, activists said, adding 11 victims to a death toll dissidents and Western powers put at over 15,000. 

French President Francois Hollande urged stiffer sanctions against Assad and more support for the rebels at the start of a meeting of Western and Arab states who back the uprising. 

"Bashar al-Assad must go," Hollande told a meeting of foreign ministers and senior diplomats from the "Friends of Syria" group. "It's in the interest of Syria, of its neighbors and everybody who wants peace in the region." 

Clinton renewed Washington's call for a UN sanctions resolution, something that was twice blocked last year by the veto power held by Russia and China in the Security Council. 

More concrete plans 

The meeting of the "Friends of Syria", the third one following those in Tunisia and Turkey, will focus on more concrete plans to support the Syrian opposition, including equipping them with communications tools, French Foreign Minister Laurent Fabius said in an interview published on Thursday. 

Friday's meeting is also expected to seek tougher sanctions against the Syrian government to mount pressure on Assad, who has told a Turkish newspaper that he would resign as long as his step-down is in the interests of his people. 

China and Russia, both permanent members of the UN Security Council, won't attend the Paris meeting. 

Russian Foreign Minister Sergei Lavrov on Tuesday criticized the one-sided purpose of the forum, saying it only sought to back the "external" Syrian opposition, which would raise confrontation instead of creating a platform for the all-Syrian dialogue without outside intervention. 

The United Nations reportedly considered reducing the number of its monitors without changing its mandate after the observer mission was forced to be suspended out of safety concerns. 

General Robert Mood, head of UN monitors in Syria, on Thursday insisted on the presence of the mission, but pledged to reconstruct the 300-strong monitoring team to boost their capacity. 

"Now we are in a situation where we have the contacts and knowledge, but we have no cease-fire. So it is time to stop spreading ourselves out too thin and restructure in a way that will allow us, once we resume our activities, to conduct targeted tasks that require longer periods of stay in particular areas," he told a press conference in Damascus. 

Also on Thursday, Iraqi Foreign Minister Hoshyar Zebari said that members of the al-Qaida militant group have crossed the border into Syria to carry out terrorist attacks. 

"Yes indeed, we have solid information and intelligence that members of al-Qaida terrorist network have gone in the other direction to Syria to help and liaise to carry out terrorist attacks," Zebari told reporters.