Assad's fall only matter of time: former U.N. Syria mission chief

OSLO (Reuters) - It is just a matter of time before the government of Syrian President Bashar al-Assad falls because its use of massive force is mobilizing insurgents, General Robert Mood, the former head of the U.N. monitoring mission in Syria, said on Friday.

"In my opinion it is only a matter of time before a regime that is using such heavy military power and disproportional violence against the civilian population is going to fall," the Norwegian general, who left Damascus on July 19, told Reuters.

"Every time there are 15 people killed in a village, 500 additional sympathizers are mobilized, roughly 100 of whom are fighters," Mood said.

However, the authoritarian Syrian leader is probably secure in the short term because he has the military capability to hold off the rebels and his eventual fall could be months or even years away, Mood said.

"In the short term it may very well be possible for him to (hold on), because the military capabilities of the Syrian army are much much stronger than those of the opposition," Mood said.

"The minute you see larger military formations leaving the ranks of the government to join the opposition, then that is when it starts accelerating ... This could last for months or even years," he said.

Mood left Syria after his 90-day mission expired - the mandate was renewed on July 20 for 30 days - and has been replaced by Lieutenant General Babacar Gaye, who has already taken up his post in Damascus.

Mood, who commanded a 400-strong mission, was unable to stop the escalating violence and said organized groups with artillery, mortars and mechanized formations were responsible for some of the violence in Syrian villages.

(Reporting by Vegard Botterli; writing by Balazs Koranyi; editing by Mark Heinrich)