Belarus will probably be the first foreign customer for Russia's top missile-defence system, a senior Russian official said Wednesday, DPA reported.
The S-400 Triumf system uses medium- and long-range missiles capable of intercepting aircraft and other missiles.
First deployed in 2007 and considered Russia's most sophisticated air defence weapon, it has never before been exported.
"Unquestionably, one of the first countries to receive the S-400 Triumf system will be Belarus, said Konstantin Biryulin, director of Russia's federal service of military-technical cooperation.
Biryulin said deliveries could begin in 2013 if Belarus follows up on a 2009 letter of intent to order 16 systems, the Interfax news agency reported. He didn't say what the price tag would be.
Belarus' military, which is closely tied to Russia's, already operates top-line Russian tanks and jet fighters.
The S-400 is similar to the US Patriot missile system, which Washington has said it wants to deploy in Poland as a defence against missiles from Iran.
Russia has criticized the US missile defence plans, saying it would be of little use against Iranian missiles.
Deployment of such a system in Eastern Europe would force Russia to deploy new weapons systems of its own, leading to an arms race, Russian President Dmitry Medvedev said at a May summit in France.
Russian Foreign Minister Sergei Lavrov is scheduled to travel to Washington in July to discuss European missile defence with his US counterpart, Hillary Clinton, the newspaper Rossiskaya Gazeta reported Wednesday.