Vladimir Putin, the Russian president, has said that Russia will not allow itself to be drawn into what he called a new arms race while saying it is developing more sophisticated weapons.
He also accused Nato and the United States of failing to respond to Moscow's security concerns, in a televised speech on Friday.
"It is already clear that a new arms race is being unleashed in the world," Putin said at a state council meeting of ministers governors and parliament members in Moscow.
Putin said "we must not allow ourselves to be drawn into this" but added Russia will "always respond" to such challenges.
Relations between Russia and Nato have been strained because of Washington's plans to station a defence shield in Europe, Moscow's suspension of a landmark arms treaty and disagreements over the future of Kosovo.
Russian concerns
Putin criticised what he calls Nato's "muscle-flexing" on Russia's borders and a planned US missile defence shield.
However, he has increased military spending during his eight-year presidency and has approved large-scale military exercises.
Defending Russia's position, Putin said: "It's not our fault, we didn't start … funnelling multi-billions of dollars into developing weapons systems."
"We drew down our bases in Cuba and in Vietnam. What did we get? New American bases in Romania, Bulgaria. A new third missile defence region in Poland," he said.
Putin said that Washington had used consultations with Moscow as "merely an information and diplomatic cover for implementing their plans."
The Kremlin has said that plans by the US to deploy 10 missile interceptors in Poland and a radar in the Czech Republic would threaten Russia's security.