Russian Deputy Foreign Minister Sergey Ryabkov told Tass on Friday that Moscow was faced with the issue of resuming nuclear tests in response to the United States adopting an "escalation course" amid rising tensions between the two countries over the war in Ukraine.

"Without prejudicing anything, I will simply say that the situation is quite complicated. It is in all its components and in all its aspects under constant review," Ryabkov replied when asked whether Russia was prepared to resume nuclear weapons tests.

Russian President Vladimir Putin suspended his country's participation in the New START treaty in 2023, accusing the US of violating its terms. The Kremlin also warned that Russia would resume nuclear testing if the US made a similar move.