President Vladimir Putin said on Tuesday that Russia was suspending participation in the New START nuclear arms reduction treaty with the United States, after accusing the West of being directly involved in attempts to strike its strategic air bases.

"I am forced to announce today that Russia is suspending its participation in the strategic offensive arms treaty,” he said.

What is the New START treaty?

Signed by then-US President Barack Obama and his Russian counterpart Dmitry Medvedev in 2010, the New START treaty caps the number of strategic nuclear warheads that the United States and Russia can deploy.

It came into force in 2011 and was extended in 2021 for five more years after US President Joe Biden took office, and allows both American and Russian inspectors to ensure that both sides are complying with the treaty.

However, inspections under the agreement were put on hold in March 2020 because of the COVID-19 pandemic.

Talks between Moscow and Washington on resuming inspections were due to take place last November in Egypt, but Russia postponed them and neither side has set a new date.

Has Russia threatened to pull out before?

Russia said earlier this month that it wanted to preserve the treaty, despite what it called a destructive US approach to arms control.

Together, Russia and the United States account for about 90 per cent of the world's nuclear warheads, and both sides have stressed that war between nuclear powers must be avoided at all costs.

However, Russia's invasion of Ukraine has pushed the two countries closer to direct confrontation than at any time in the past 60 years.

The United States has accused Russia of violating the treaty, saying Moscow was refusing to allow inspection activities on its territory.