The presidents of Turkey and Iran on Tuesday vowed to press on with their alliance alongside Russia over Syria, the Turkish presidency said Tuesday, after Ankara backed strikes by the U.S. and its allies against the Assad regime.

"The two leaders emphasized the importance of continuing the joint efforts of Turkey, Iran and Russia... to protect Syrian territorial integrity and find a lasting, peaceful solution to the crisis," a Turkish presidential source said following telephone talks between President Recep Tayyip Erdoğan and Iranian counterpart Hassan Rouhani.

The two leaders also discussed bilateral relations, said the source, who refused to be named due to restrictions on speaking to the media.

Stating Turkey's clear stance against the use of chemical weapons, Erdoğan said it is important to not allow tensions to escalate and evaluate the incidents within its context.

The leaders spoke about Syria's territorial integrity, adding that it was important to continue the joint efforts by Turkey, Iran and Russia for a lasting political solution to the Syrian crisis as part of the Astana peace process.

Also, the leaders expressed their desire to boost bilateral economic relations.

The phone call came after the U.S. in coordination with France and the U.K. conducted on Saturday a series of military strikes targeting the Assad regime's chemical weapons capabilities in retaliation to a suspected chemical attack in Douma, eastern Ghouta, earlier this month.