The Intermediate-Range Nuclear Forces Treaty (INF) was signed by US President Ronald Reagan and Soviet leader Mikhail Gorbachev in 1987. It banned missiles with ranges between 500 and 5,500 km (310-3,400 miles). But earlier this year the US and Nato accused Russia of violating the pact by deploying a new type of cruise missile, which Moscow has denied. The Americans said they had evidence that Russia had deployed a number of 9M729 missiles nown to Nato as SSC-8. This accusation was then put to Washington's Nato allies, which all backed the US claim.
"Russia is solely responsible for the treaty's demise," Secretary of State Mike Pompeo said in a statement on Friday.
"With the full support of our Nato allies, the United States has determined Russia to be in material breach of the treaty, and has subsequently suspended our obligations under the treaty," he added.
Russia's foreign ministry confirmed the INF treaty was "formally dead" in a statement carried by state-run Ria Novosti news agency.
