"Our wish is for our neighbour, Syria, to find the peace and tranquility it has been dreaming of for 13 years," said Erdogan, a key player in the region, adding that Syria "is tired of war, blood and tears".

Turkey, which has a long border with Syria, has become home to about three million Syrian refugees since the start of the civil war in 2011.

"Our Syrian brothers and sisters deserve freedom, security and peace in their homeland," Erdogan added, voicing hope "to see a Syria where different identities co-exist in peace".

"We hope to see such a Syria in the very near future," he said in a speech delivered in the southeastern city of Gaziantep, to which several hundred thousand Syrians fled.

The Turkish president was long a supporter of the resistance to Assad since the civil war erupted.

But in recent months Erdogan tried to reconcile with his Syrian counterpart -- an olive branch he accused Assad of not grasping.

"There is now a new political and diplomatic reality in Syria," he told the crowd in Gaziantep, accusing Damascus of not having grasped "the hand extended by Turkey" through Russian mediation.