Saudi Arabia's Foreign Minister, Prince Saud al-Faisal, said on Tuesday Riyadh had invited Iran's foreign minister to visit the kingdom.

"We sent an invitation to the foreign minister to visit Saudi Arabia, but this intention to visit has not become a fact ... But any time he sees fit to come, we are ready to receive him," Prince Saud told reporters at a news conference in the Saudi capital Riyadh.

Saudi Arabia is a leading backer of rebels fighting against Syrian President Bashar al-Assad, who is a close ally of the kingdom's main rival, Shi'ite Muslim power Iran.

"We'll negotiate with them, we'll talk with them," Prince Saud said.