Responding to a question about the risk of a new arms race, Putin told his annual news conference: "It happened already, and this is obvious."
Putin earlier urged Washington to agree a one-year extension of the New START treaty, the last remaining agreement maintaining the nuclear balance between the two countries, which expires in February.
He said he believed U.S. President-elect Joe Biden was open to dialogue on the issue, but "we need some reaction from our American partners".
The New START (Strategic Arms Reduction Treaty) accord, signed in 2010, limits the numbers of strategic nuclear warheads, missiles and bombers that Russia and the United States can deploy.