President Vladimir Putin today said tests of new Russian missiles this week were a response to US plans for missile defence sites in Europe.
The Russian leader also criticised US "imperialism" in global affairs and warned of an arms race to maintain a global strategic balance.
"It wasn't us who initiated a new round of an arms race," Mr Putin said when asked about Russia's missile tests.
He said the testing of a new ballistic missile capable of carrying multiple nuclear warheads and a new cruise missile was part of a response to the planned deployment of new US military bases and missile defence sites in ex-Soviet satellites in central and eastern Europe.
He criticised the US and other Nato members for failing to ratify an amended version of the 1990 Conventional Forces in Europe (CFE) treaty, which limits the deployment of heavy non-nuclear weapons around the continent.
"We have signed and ratified the CFE and are fully implementing it. We have pulled out all our heavy weapons from the European part of Russia to behind the Ural Mountains and cut our military by 300,000 men," Mr Putin said.
"And what about our partners? They are filling eastern Europe with new weapons. A new base in Bulgaria, another one in Romania, a site in Poland and a radar in the Czech Republic," he said. "What we are supposed to do? We can't just sit back and look at that."
Mr Putin and other Russian officials have repeatedly rejected US assurances that the planned missile defence installations are meant to counter a potential threat from nations such as Iran and pose no danger to Russia.
AP