Russian is the official language of Russia , Belarus , Kazakhstan , Kyrgyzstan and Uzbekistan , also Russian is official language of unrecognized countries Abkhazia , South Osetia and Transnistia . It is also an official language of Belarus , Kazakhstan , Kyrgyzstan , and the de facto official language of the unrecognized country of Transnistria and partially recognized countries of South Ossetia and Abkhazia .