Secretary of State Mike Pompeo announced Friday that the US is suspending the Intermediate-Range Nuclear Forces Treaty, a key pact with Russia that has been a centerpiece of European security since the Cold War.
"Russia's violations put millions of Europeans and Americans at greater risk," Pompeo said, adding, "It is our duty to respond appropriately."
Pompeo, speaking from the State Department briefing room, said the US had provided "ample time" to Russia to return to compliance.
"For years, Russia has violated the terms of the Intermediate-Range Nuclear Forces Treaty without remorse," Pompeo said.
The suspension, which raises concerns about a renewed arms race with Moscow and has put European allies on edge, goes into effect on Saturday. Pompeo's announcement starts a 180-day clock to complete withdrawal unless Russia returns to compliance with the 1987 agreement.
President Donald Trump and his senior officials had been signaling for months that they were ready to pull out of the INF treaty, which the US and Europe accuses Moscow of violating since 2014.
"The United States has fully adhered to the INF Treaty for more than 30 years, but we will not remain constrained by its terms while Russia misrepresents its actions," Trump said in a statement Friday. "We cannot be the only country in the world unilaterally bound by this treaty, or any other."