Russia's foreign ministry said on Wednesday that demands from the United States to resume inspections under the New START nuclear arms control treaty were "cynical" given Washington's support for Ukraine.

The ministry also warned that Washington's actions towards Russia posed a "real risk" of a direct military clash between the two nuclear powers, the RIA news agency reported.

"The demands of the United States to renew inspections at Russian sites are clearly cynical," RIA quoted the ministry as saying in a statement that also accused Washington of seeking to inflict a "strategic defeat" on Russia in Ukraine.

New START caps the number of strategic nuclear warheads that the United States and Russia can deploy, and the deployment of land- and submarine-based missiles and bombers to deliver them.

The treaty came into force in 2011 and was extended in 2021 for five more years. Talks between Moscow and Washington on resuming inspections under the treaty were scheduled for last November but were called off at the last moment.

Russia said last week it wanted to preserve New START, its last remaining nuclear treaty with the United States, despite what it called a destructive U.S. approach to arms control.

"The Russian side again confirms its unchanged adherence to the New START treaty as an important instrument for maintaining international security and stability," the ministry said in Wednesday's statement.

Together, Russia and the United States account for about 90% of the world's nuclear warheads.

The future of New START has taken on added importance at a time when Russia's invasion of Ukraine has pushed the two countries closer to direct confrontation than at any time in the past 60 years.