Peculiarities of transit through the states of CIS
“Passenger should follow passport administrative (visa included), customs and other regulations, set for travelling by railway transport international communications, as for oneself as for one’s personal luggage. Railway has no right to control following of the aforesaid is not responsible for consequences stemming out of their non-fulfillment by a passenger.”
Article 45 section IX “Agreement on international communication” and OP SMPS
For information on documents and requirements when passing the boarder between the Russian Federation and countries of near and far abroad, it is necessary to refer to appropriate diplomatic representatives or embassies in Moscow and to the Departments for Visas and Registrations in one’s location.
On passengers transit passing through Mongolia territory in compliance with RF MFA notification, passengers should have transit visa, which is issued in the consulate of the Mongolian embassy in Moscow, Irkutsk and Ulan Ude only on final departure country visa availability. | 
