MOSCOW, Dec 5 (Reuters) - Russia's National Card Payment System (NSPK) said on Tuesday it had launched its Mir payment cards in Cuba, making the Caribbean island one of only a handful of countries to join Moscow's alternative to Visa and Mastercard.

Payment cards issued by Mir have become more important since its U.S. rivals suspended operations in Russia after Moscow sent tens of thousands of troops into Ukraine, and their payment cards which were issued in the country stopped working abroad.

The NSPK said the cards will first be accepted in popular tourist locations, including the Cuban capital Havana and the resort town of Varadero.

Russia has been courting 'friendly' countries - those which have not imposed sanctions against Moscow over its actions in Ukraine - but has stopped of disclosing which accept the cards.

However, banks in some of these countries, including Turkey, Kyrgyzstan and Tajikistan, halted Mir transactions after the U.S. Treasury included NSPK's head on its sanctions list and suggested those working with NSPK could also face restrictions.

The limited reach of Russian bank cards highlights the wider issue of Moscow's isolation on the global stage. Although many countries have stopped short of imposing sanctions on Russia, very few are keen to display open support. (Reporting by Reuters; Writing by Maxim Rodionov; Editing by Alexander Smith)