The US has raised concerns with Moscow over a reported Russian test of a cruise missile and is evaluating whether it breaks a 1987 treaty, a US official said.
Washington has raised "the possibility of... a violation", State Department spokeswoman Jen Psaki said, amid reports that Russia had tested a new ground-launched cruise missile.
The New York Times said Thursday that Moscow had begun testing the new missile as early as 2008, and that the State Department's senior arms control official Rose Gottemoeller had repeatedly raised the issue with Moscow since May.
Psaki said she could not refute the details of the Times report, and there was an ongoing interagency review to determine whether the Russians had violated the terms of a US-Russian arms control pact.
The 1987 Intermediate-Range Nuclear Forces Treaty (INF), signed by then US president Ronald Reagan and his Russian counterpart Mikhail Gorbachev, eliminated nuclear and conventional intermediate range ground-launched ballistic and cruise missiles.
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"The important note here is that there's still an ongoing review, an interagency review determining if there was a violation," Psaki stressed, adding the consultations had been continuing for some months.
"We do of course take questions about compliance with arms control treaties, including the INF Treaty, very seriously."
A NATO official said "this is a serious matter" adding that the treaty was "a key component of Euro-Atlantic security."
"Compliance with arms control treaties is a fundamental requirement if we are to have more transparency in our dialogue with Russia. NATO allies consult at all times on all matters relevant to their security," the official added.
