U.S. Defense Secretary Jim Mattis said Thursday Russia's violation of a global arms control treaty is "untenable" and warned the U.S. would be forced to match Moscow's military capabilities if it continues to violate the pact.
The U.S. maintains Russia's Novator 9M729 cruise missile violates the 1987 Intermediate-Range Nuclear Forces Treaty, a Cold War-era agreement that bans medium-range missiles capable of striking Europe or Alaska. The treaty bans all nuclear and conventional ground-launched and cruise missiles of intermediate range.
Mattis told reporters Thursday after a NATO defense ministers meeting in Brussels the U.S. is reviewing its military and diplomatic options because of Russia's continued violation of the treaty.
"Russia must return to compliance with the INF Treaty or the U.S. will need to match its capabilities to protect U.S. and NATO interests. Make no mistake, the current situation with Russia in violation of this treaty, is "untenable," Mattis said.
WATCH: Allies Warn Russia Against Violation of International Laws
U.S. Ambassador to NATO Kay Bailey Hutchinson said if Russia does not comply with the treaty, the U.S. will explore ways to "take out" Russia's cruise missile system. She later said she did not mean the U.S. would strike Russia pre-emptively, but wanted to emphasize the importance of Moscow's adherence to the treaty.
Russia has consistently denied any such violation and has asserted that the U.S. has positioned missile defense systems in violation of the pact.
The U.S. initially accused Moscow early last year of deploying the cruise missile system.
Mattis' remarks may exacerbate U.S.-Russia relations, which have deteriorated to their lowest point since the end of the Cold War due to Russia's 2014 seizure of Crimea, its continuous bombing of Syria and it's meddling in the 2016 U.S. presidential election.