Syria's leading opposition coalition is to decide Tuesday whether to attend peace talks in Geneva, following a tense meeting with US Secretary of State John Kerry, a member told AFP on Monday.

The member of the so-called High Negotiations Committee said Kerry applied "pressure" during a weekend meeting in Saudi Arabia, warning the opposition risked "losing friends" if they failed to attend the talks.

Fuad Aliko said the Committee would meet Tuesday to make a final decision on whether to attend the Geneva talks.

The Saturday meeting with Kerry was "neither comfortable, nor positive", said Aliko, a member of the Committee's designated delegation for the talks.

Kerry told the Committee's chief Riad Hijab that they risked "losing friends", Aliko said.

"This talk means a halt to political and military support to the opposition," he added.