Lt. Gen. Sergei Rudskoi of the military's General Staff said nine Russian warplanes and eight Turkish jets have taken part in the strikes on the outskirts of al-Bab in the province of Aleppo.

Rudskoi's statement on Wednesday was the first acknowledgement of the Russian strikes in support of the Turkish offensive on al-Bab.

It highlighted an increasingly close alliance between Russia and Turkey, which last month jointly brokered a Syria truce and are working to prepare Syrian talks in Kazakhstan next week, AP reported.

The two nations have backed opposing sides in the nearly six-year Syrian conflict, with Moscow supporting Syrian President Bashar Assad and Ankara backing his foes.