"If the Syrian state has a real position, with the capabilities it has, it should stand in the face of this aggression and say that it will not allow Turkish planes to fly in Syrian airspace," said Othman Al-Sheikh Issa.

Al-Sheikh Issa is the co-chair of Afrin's executive council.

Turkey launched an offensive against the Kurdish People's Protection Units (YPG) on Saturday in their enclave of Afrin, supporting Syrian rebels with air strikes and ground troops.

Afrin is governed by a semi-autonomous administration dominated by Kurdish parties, and Syrian government troops have not had a presence there for several years.

"We consider Afrin an inseparable part of Syrian territory. Any attack on Afrin is an attack on all the region's people and on the sovereignty of the Syrian state," said Al-Sheikh Issa.

"This is why we called on the Syrian state to break its silence and demonstrate its position towards this ruthless aggression," he told AFP.

His comments came after the local authority in the Afrin district called on Syria's government to do more to protect its borders.

"We call on the Syrian state to do its sovereign duty towards Afrin and protect its borders with Turkey from the Turkish occupier's attacks... and deploy its armed forces to protect the borders," said the statement.

Syrian President Bashar al-Assad on Sunday condemned Turkey's assault and last week Deputy Foreign Minister Faisal Mekdad warned government forces could shoot down Turkish warplanes.