The Kremlin on Wednesday defended its decision to station tactical nuclear weapons in Belarus, rejecting criticism of the move by NATO Secretary-General Jens Stoltenberg.
Kremlin spokesman Dmitry Peskov told reporters that the U.S.-led transatlantic alliance was the one expanding towards Russia, not the other way round, and therefore Moscow had to take steps to defend its own security.
Stoltenberg said on Wednesday that Russia's move belied a recent joint Russian-Chinese statement that said countries should not deploy nuclear weapons outside their borders.
"It is NATO that is expanding towards Russia, not Russia that is taking its military infrastructure towards the borders of NATO," Peskov said on Thursday, when asked to respond to Stoltenberg's remarks.
Finland joined the NATO alliance on Tuesday, doubling the length of the alliance's land border with Russia, and Sweden is also set to join - moves triggered by Russia's despatch of its armed forces into neighbouring Ukraine last year.
Moscow said it would keep a close eye on any NATO military deployments to Finland and respond accordingly.
"This movement adds to our concerns and worries for our safety ... and we are taking measures to ensure our security. And so it will be every time NATO approaches our borders, in order to rebalance the security architecture on the continent," Peskov said.
President Vladimir Putin was hosting his Belarusian counterpart Alexander Lukashenko in Moscow on Thursday for talks, where the issue of Russia's deployment of nuclear weapons to its neighbour was likely to be discussed.
Russia has not given a clear timetable for moving tactical nuclear weapons to Belarus, but Putin said the construction of storage facilities should be complete by the start of July.
It will be the first deployment of part of Russia's nuclear arsenal outside its borders since the collapse of the Soviet Union.
(Reporting by Reuters; Editing by Kevin Liffey)