US President Donald Trump has announced that America was pulling out of the landmark Intermediate-Range Nuclear Forces Treaty (INF) with Russia, a decades-old agreement signed in 1987.
"Russia has violated the agreement. They've been violating it for many years," Trump told reporters on Saturday before boarding Air Force One to leave Nevada following a campaign rally.
"And I don't know why President (Barack) Obama didn't negotiate or pull out. And we're not going to let them violate a nuclear agreement and go out and do weapons and we're not allowed to.We're the ones that have stayed in the agreement and we've honoured the agreement.
"But Russia has not, unfortunately, honoured the agreement. So we're going to terminate the agreement. We're gonna pull out," he said of the agreement, which was signed in December 1987 by former President Ronald Reagan and former USSR President Mikhail Gorbachecv.
It offered a blanket of protection to the US' European allies and marked a watershed agreement between two nations at the centre of the arms race during the Cold War.
The Trump administration has said repeatedly that Russia has violated the treaty and has pointed to their predecessors in the Obama administration who accused Moscow of violating the terms of the agreement.
In 2014, CNN reported that the US had accused Russia of violating the INF Treaty, citing cruise missile tests that dated to 2008.
The US at the time informed its NATO allies of Russia's suspected breach.
Earlier this month, NATO Secretary General Jens Stoltenberg said that the military alliance remained "concerned about Russia's lack of respect for its international commitments, including the Intermediate-Range Nuclear Forces Treaty, the INF Treaty".
Moscow's failure to adhere to the agreement was also addressed in the most recent Nuclear Posture Review published by the US Defence Department in February, which said Russia "continues to violate a series of arms control treaties and commitments".
However, pulling out of the treaty could provoke a similar arms race across Europe akin to the one that was occurring when the agreement was initially signed in the 1980s, CNN said.