The US is set to formally withdraw from a nuclear treaty with Russia, raising fears of a new arms race.

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 - known to Nato as SSC-8. This accusation was then put to Washington's Nato allies, which all backed the US claim.

BBC