Russia on Monday slammed as "one-sided" last week’s Friends of Syria meeting in Tunisia that vowed further sanctions against the Syrian regime.

Russia on Monday slammed as "one-sided" last week's Friends of Syria meeting in Tunisia that vowed further sanctions against the Syrian regime.

"The meeting that was held in Tunisia was clearly one-sided... It is clear to us that this meeting did not help create conditions that would stimulate all sides to seek a political solution," Foreign Minister Sergei Lavrov told reporters.

Russia boycotted the meeting after arguing that Arab and Western participants were unfairly blaming one side of an "internal conflict" for violence.

Moscow has infuriated the West by refusing to single out President Bashar Assad's regime over the crisis and its assertion that both government forces and the opposition bear equal responsibility for the violence.

Lavrov stressed that the West's obligation to use its good standing with the Syrian opposition is to call "on everyone who is shooting there to halt (the violence) as soon as possible."

He also welcomed the constitutional referendum that Assad staged on Sunday as "an important step" and "movement toward democratization".