Leaving the INF treaty would allow the Trump administration to counter the Chinese (Picture: PA).
The US has announced it is pulling out of a treaty with Russia which has been a centrepiece of nuclear arms control since the Cold War.
The withdrawal had been expected for months, and follows years of unresolved dispute over Russian compliance with the 1987 pact, which bans certain ground-launched cruise missiles.
Russia denies violating the treaty, but US secretary of state Mike Pompeo said Washington will suspend its obligations to the pact on Saturday and if Moscow does not come into compliance, it "will terminate".
Mr Pompeo told reporters in Washington: "We provided Russia with an ample amount of time to mend it's ways, and for Russia to honour it's commitment, tomorrow that time runs out.
"Russia has refused to take any steps to turn real and verifiable compliance over these 60 days, the United States will therefore suspend it's obligations under the INF Treaty, effective February 2nd.
"Russia has jeopardised the United States' security interest and we can no longer be restricted by the Treaty while Russia shamely violates it."
Mike Pompeo made the announcement in Washington.
US officials have also expressed concern that China, which is not part of the treaty, is deploying large numbers of missiles in Asia that the US cannot counter because it is bound by the treaty.
Leaving the INF treaty would allow the Trump administration to counter the Chinese, but it is unclear how it would do that.
The Intermediate-Range Nuclear Forces, or INF, treaty was the first arms control measure to ban an entire class of weapons: ground-launched cruise missiles with a range between 310 and 3,100 miles.
NATO said Russia is in breach of the treaty, saying that 'unless the country honours its obligations', the country will "bear sole responsibility for the end of the treaty":
"NATO continues to closely review the security implications of Russian intermediate-range missiles and will continue to take steps necessary to ensure the credibility and effectiveness of the Alliance’s overall deterrence and defence posture.
"We will continue to consult each other regularly with a view to ensuring our collective security."
"We urge Russia to use the remaining six months to return to full and verifiable compliance to preserve the INF Treaty."
NATO added that the allies "fully support" America's decision.
Secretary of State Mike Pompeo said in early December that Washington would give Moscow 60 days to return to compliance before it gave formal notice of withdrawal, with actual withdrawal taking place six months later.
Technically, a US withdrawal would take effect six months after this week's notification, leaving a small window for saving the treaty, but in talks this week in Beijing, the US and Russia reported no breakthrough in their dispute, leaving little reason to think either side would change its stance.
Nuclear weapons experts at the Carnegie Endowment for International Peace said in a statement this week that while Russia's violation of the INF treaty is a serious problem, US withdrawal under current circumstances would be counter-productive.
"Leaving the INF treaty will unleash a new missile competition between the United States and Russia," they said.