Russia tested a ground-launched cruise missile, breaking the Intermediate-Range Nuclear Forces Treaty signed in 1987 during the Cold War, the US said.
A senior US official did not provide further details on the alleged breach, but described it as “very serious”.
The bilateral agreement banned medium-range missiles with ranges between 300 to 3,400 miles.
The US claims come at a time of heightened tensions between the two sides, with the US criticizing Russia for its alleged involvement in the conflict in Ukraine.
A senior US official, who was not named, said in a statement that the testing of the missile was “a very serious matter which we have attempted to address with Russia for some time now”.
“We encourage Russia to return to compliance with its obligations under the treaty and to eliminate any prohibited items in a verifiable matter,” the official added.
President Barack Obama has written to President Vladimir Putin over the matter, officials say.
This is the first time the US government has made its accusations public, though the issue has simmered for years.
In January, the New York Times reported that US officials believed Russia had began testing ground-launched cruise missiles as early as 2008.
The US State Department had said at the time that the issue was under review.
The 1987 treaty is at the heart of American-Russian arms control efforts, and was signed by then-Presidents Ronald Reagan and Mikhail Gorbachev in the final years of the Cold War.
c9W6XGncEk4Image source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…