Dmitry Mezentsev

Dmitry Fyodorovich Mezentsev (; born 18 August 1959, Leningrad) is a Russian politician and diplomat. Previously he was Ambassador of Russia to Belarus between 30 April 2019 and 19 March 2021, a senator from Sakhalin Oblast (2015—2019), General Secretary of Shanghai Cooperation Organisation (2012—2015) and Governor of Irkutsk Oblast (2009—2012). 
In 2012 Mezentsev ran for President of Russia, but was rejected by the Central Election Commission.
2012 presidential campaign.
Mezentsev tried to run for President of Russia in 2012. On 14 December 2011, the trade Union Committee of the East Siberian railway nominated Dmitry Mezentsev as a presidential candidate. His candidacy was supported by the then President of Russian Railways Vladimir Yakunin. However, the CEC rejected Mezentsev's candidacy, as after checking the signatures collected in his support, too many signatures were not recognized as valid.
On 19 March 2021, Mezentsev was relieved of his post as ambassador to Belarus by presidential decree. On the same day President of Belarus Alexander Lukashenko appointed Mezentsev State Secretary of the Union State of Russia and Belarus, replacing Grigory Rapota.