What is INF and why has the US suspended the nuclear arms treaty with Russia?

BOTH Donald Trump and Vladimir Putin have recently announced they will be pulling out of the Intermediate-Range Nuclear Forces Treaty (INF).

But what is the INF and why are they withdrawing from it? Here's what you need to know.

What is the INF?

The Intermediate-Range Nuclear Forces Treaty (INF) is an agreement between the U.S. and Russia to control arms.

It was signed in 1987 in Washington D.C. by President Ronald Regan and Soviet Union General Secretary Mikhail Gorbachev.

The INF Treaty eliminates land-based ballistic and cruise missiles, and their launchers, with ranges of 500-1,000 kilometres (310-620 miles) - known and short medium-range - and 1,000-5,500 kilometres (620-3,420 miles) - known as intermediate range.

The treaty does not cover air or sea launching missiles.

By May 1991, 2,692 missiles had been eliminated and 10 years of on-site verification inspections followed.

The immediate effect eliminated the US' Pershing II missiles and the Soveiet Union's SS-20s - which was a key event in ending the Cold War.

Why has the U.S. pulled out of the INF?

President Donald Trump announced his intention to pull the U.S. out of the treaty on October 20, 2018.

He claimed his reason for doing so was because Russia had been "violating it for many years".

Reports claim another reason for the pull-out is a U.S. need to counter a Chinese arms buildup in the Pacific, as China is not a signatory of the treaty.

On February 1, 2019, U.S. Secretary of State Mike Pompeo announced the United States would withdraw from the treaty on February 2, with a six-month timeline for full withdrawal and INF treaty termination if the Russian Federation does not come back with compliance.

A number of nuclear arms control experts urged Trump to preserve the treaty.

The decision was criticised by chairmen of the United States House of Representatives Committees on Foreign Affairs and Armed Services who said that instead of crafting a plan to hold Russia accountable and pressure it into compliance, the Trump administration has offered Putin an easy way out of the treaty and has played right into his hands.

What has Vladimir Putin said about it?

On February 2, 2019, Russian President Vladimir Putin announced Russia was also suspending the INF Treaty in a "mirror response" to President Trump's decision, effective that day.

On February 3 Russia began work on new hypersonic missiles and adopted a policy to avoid initiating disarmament talks with the United States.

Announcing the plans, Putin threw shade at Donald Trump - suggesting he is too "immature" for meaningful talks.

He said: "Our American partners have announced they are suspending their participation in the deal, and we are also suspending our participation.

"We will wait until our partners have matured enough to conduct an equal, meaningful dialogue with us on this important topic."