Damascus and Tehran have held Sunni Muslim Gulf Arab states and Turkey, all allies of the United States and European powers, responsible for the bloodshed in Syria by supporting the overwhelmingly Sunni Muslim rebels. Western powers sympathetic to the rebels are concerned that anti-Western Sunni Islamists could benefit from a victory for the anti-Assad forces.
Iran's Fars news agency said Jalili told Assad that Iran was prepared to provide humanitarian aid to Syria.
On a fence-mending visit to Turkey, Iranian Foreign Minister Ali Akbar Salehi said he wanted to work with Ankara to resolve the crisis. Turkish Prime Minister Tayyip Erdogan described as "worrying" a comment on Monday by Tehran's top general, who blamed Turkey, Saudi Arabia and Qatar for bloodshed in Syria.
Iran has expressed fears for more than 40 Iranians it says are religious pilgrims kidnapped by rebels from a bus in Damascus while visiting Shi'ite shrines. Salehi wrote to U.N. Secretary-General Ban Ki-moon seeking his help to free them.
Rebels say they suspect the captives were troops sent to help Assad. A rebel spokesman in the Damascus area said on Monday three of the Iranians had been killed by government shelling. He initially said the rest would be executed if the shelling did not stop but later said they were being questioned.