Russia's deployment of nuclear-capable missiles in violation of arms treaty is "untenable", says Mattis

Defense Secretary Jim Mattis on Thursday said Russia's deployment of nuclear-capable missiles in violation of an arms treaty is "untenable" and unless Moscow changes, the US will have to match that military capability.

Speaking to reporters at the close of a NATO defence ministers meeting, Mattis said the US is reviewing its diplomatic and military options because of Russia's continued violation of the 1987 Intermediate-range Nuclear Forces Treaty.

"Russia must return to compliance with the INF Treaty or the US will need to match its capabilities to protect US and NATO interests," Mattis said in prepared remarks.

"Make no mistake: The current situation, with Russia in blatant violation of this treaty, is untenable." His comments underscored assertions made Tuesday by Kay Bailey Hutchinson, the US ambassador to NATO.

She warned that unless Russia complies with the treaty, the U.S. will be looking at ways to "take out" the system. America, she said, doesn't want to violate the treaty but Russia could force its hand.

She later said she wasn't talking about preemptively striking Russia, but making the point that Moscow needs to adhere to the treaty.

The US has argued that Russia's 9M729 system violates the Cold War-era pact that bans an entire class of weapons — all nuclear and conventional ground-launched ballistic and cruise missiles of intermediate range. The treaty was a landmark in arms control in the final years of the Cold War.

The US first accused Russia early last year of deliberately deploying a land-based cruise missile in order to pose a threat to NATO.

Russia has claimed that US missile defences violate the pact. In the past, the Obama administration worked to convince Moscow to respect the INF treaty but made little progress.

(With inputs from agencies.)