The United States accused Russia of violating New START, the last remaining nuclear treaty between the two countries. According to the U.S. State Department, Moscow is refusing to allow America to inspect its nuclear facilities.

"Russia’s refusal to facilitate inspection activities prevents the United States from exercising important rights under the treaty and threatens the viability of U.S.-Russian nuclear arms control," a State Department spokesperson told Reuters.

The New Strategic Arms Reduction Treaty is an Obama-era arms reduction treaty that has the goal of halving the number of deployed strategic nukes of both countries. Key to the treaty’s enforcement is mutual inspections. Moscow is supposed to come to the U.S. and inspect its nuclear sites, and Washington can do the same. Now the U.S. is saying that Moscow won’t let it conduct inspections.

“All Russia needs to do is allow inspection activities on its territory, just as it did for years under New START, and meet in a session of the Bilateral Consultative Commission,” the State Department said in a statement. “There is nothing preventing Russian inspectors from traveling to the United States and conducting inspections.”

New START was on shaky ground before this. The treaty went into force in 2011 and almost lapsed during Trump’s presidency because he thought it was a bad deal. On the first day of his presidency, Biden renewed the treaty and it’s now set to expire in 2026.

But New START may not even make it to 2026. Russia has become belligerent around its nuclear weapons programs since it escalated its war in Ukraine in February of 2022. It repeatedly teased the construction of new nuclear weapons and, earlier this week, said that the renewal of New START might be contingent on its victory in Ukraine.

The U.S. and Russia were supposed to meet in Cairo in November of 2022 to discuss the treaty, but Moscow didn’t show. Earlier this week, Russia’s Deputy Foreign Minister Sergei Ryabkov told state-run news agency RIA Novosti that he thought the treaty was being used to hold Russia hostage and that the dissolution of the treaty was “quite a possible scenario.”