North Azerbaijani, or Northern Azerbaijani, is the official language of the Republic of Azerbaijan. It is closely related to the modern-day Istanbul Turkish, the official language of Turkey. It is also spoken in southern Dagestan, along the Caspian coast in the southern Caucasus Mountains and in scattered regions throughout Central Asia. As of 2011, there are some 9.23 million speakers of North Azerbaijani including 4 million monolingual speakers (many North Azerbaijani speakers also speak Russian, as is common throughout former USSR countries).