"Iran believes Syria has the right to legitimate self-defence. To cover their crimes in the region, Israeli officials are resorting to lies against other countries," foreign ministry spokesman Bahram Ghasemi told AFP.

Israel struck targets inside Syria on Saturday after intercepting what it said was an Iranian drone entering its airspace from Syria, which it labelled an "attack."

An Israeli fighter jet crashed under fire from Syrian air defences.

That prompted Israel to unleash a dozen retaliatory strikes on both Syrian and Iranian targets inside Syria.

Iran issued a joint statement alongside the other main allies of the Syrian regime, Russia and Lebanese militant group Hezbollah, denying the allegations regarding the drone.

"The statement by the Israeli enemy that it was targeted by a drone which entered the airspace of occupied Palestine, is nothing but lies and allegations," the statement said.

It said the Israeli air strikes had targeted drones used in the fight against "terrorist organisations, primarily Daesh", using an alternative name for the Islamic State group.

The statement vowed a "relentless response" to "all further aggression".

"Iran does not have a military presence in Syria, and has only sent military advisers at the request of the Syrian government," Ghasemi told AFP.

"We deny all unfounded allegations by the Zionists. The government and Syrian army are only defending themselves against Israeli aggression."