Russia, Iran and Turkey agreed on Tuesday to guarantee Syria peace talks and backed expanding a ceasefire in the war-torn country, Russian foreign minister said after talks with counterparts.

"Iran, Russia and Turkey are ready to assist in preparing the agreement in the making between the Syrian government and the opposition and to become its guarantor," Russian Foreign Minister Sergei Lavrov said, citing a joint statement. 

"The ministers agree with the importance of widening the ceasefire, of free access for humanitarian aid and movement of civilians onto Syrian territories," he added.