The Cold War-era agreement was hailed as historic when it was signed in 1987 in Washington by US president Ronald Reagan and Soviet leader Mikhail Gorbachev.

It opened the way to a new era in relations between the Eastern and Western blocs.

- To be destroyed -

Other nuclear accords had already been concluded, including SALT I in 1972 and SALT II in 1979, freezing the number of strategic ballistic missile launchers held by each country.

But the INF banned conventional and nuclear missiles that can travel between 500 and 5,500 kilometres (310 and 3,400 miles) and said they were to be destroyed.

It led to the destruction of 2,692 missiles by 1991, almost all the intermediate range which made up a little more than four percent of the total nuclear arsenals of the two countries in 1987.

One of the innovations of the INF treaty was that inspectors could verify in the other country that the missiles had been destroyed.

- Dangerous arms race -

The treaty put an end to a mini-arms race triggered by the Soviet Union's deployment of SS-20 nuclear missiles targeting Western European capitals.

NATO had responded by deploying US nuclear-tipped Pershing IA and II missiles. This led to massive pacifist demonstrations across Europe.

During what was known as the Euromissiles crisis, Reagan described the Soviet Union as "the evil empire".

The arrival in power of Gorbachev in 1985 and his Perestroika reforms, however, signalled the opening of the Soviet bloc to dialogue with the United States.

Three summits between Gorbachev and Reagan between 1985 and 1987 were necessary to agree to sign the INF treaty.

- Declared dead -

The US and NATO alliance have for years complained that Russia's new ground-launched 9M729 missile can travel further than the limits outlined in the INF treaty.

In October 2018, President Donald Trump accused Russia of not respecting the accord and threatened to withdraw.

Washington formally abandoned the pact on August 2, 2019.

NATO said Russia was solely to blame for the demise of the accord, citing risks posed by the 9M729 to Allied security.

Moscow in turn blamed Washington and called for a moratorium on deploying intermediate-range nuclear missiles.