Russia's foreign minister on Tuesday invited Tajikistan into "integration structures" within the Moscow-dominated post-Soviet group, the Commonwealth of Independent States.
"The Customs Union and the Common Economic Space are open at any stage of formation for the joining of other countries which share the principles of Eurasian integration and are ready to realize them," Foreign Minister Sergei Lavrov said at a university in the Tajik capital of Dushanbe.
He said Tajikistan would be "comfortable."
The Customs Union, an economic alliance which removes customs barriers between Russia, Belarus and Kazakhstan, was established in 2010 and took effect last year. Ukraine has indicated it wants closer ties with it, but Kiev's EU ambitions have caused concern in the Kremlin.
The Common Economic Space between the three Customs Union countries took effect from January 1 this year.
