Russia is suspending its participation in the New START nuclear arms reduction treaty, President Vladimir Putin said on Tuesday.

Moscow is not withdrawing from the deal, but is suspending its participation, Putin said in his state of the nation address.

Under the key nuclear arms control treaty, both the United States and Russia can conduct inspections of each other’s weapons sites, but the inspections have been halted since 2020 due to the Covid-19 pandemic.

However, the new START treaty remains in effect after a previous agreement between Moscow and Washington extended it until February 4, 2026.

According to US officials, Russia has consistently refused to allow inspections of its nuclear facilities.

“Russia is not fulfilling its obligation under the New START Treaty to facilitate inspection activities on its territory,” a US State Department spokesman said in January.

“Russia’s refusal to facilitate inspection activities prevents the United States from exercising important rights under the treaty and threatens the viability of US-Russia nuclear arms control.”

Some context: The New START treaty is the only remaining agreement to regulate the world’s two largest nuclear arsenals.

The treaty places limits on the number of deployed intercontinental-range nuclear weapons that both the US and Russia can have. It was last extended in early 2021 by five years, meaning the two sides will soon need to start negotiating another arms control deal.

A session of the Bilateral Consultative Commission on the treaty was scheduled to meet in Egypt at the end of November, but was abruptly cancelled.

The United States blamed Russia for this postponement, and a State Department spokesperson said the decision was made “unilaterally” by Russia.