Russia has issued a warning that it will retaliate if any country—particularly the United States—resumes nuclear testing, according to Deputy Foreign Minister Sergey Ryabkov. Speaking to reporters and the State Duma, Ryabkov accused Washington of maintaining nuclear test infrastructure in a state of readiness and signaled that Moscow is closely monitoring U.S. actions. The comments follow Russian President Vladimir Putin’s remarks at the Valdai International Discussion Club, where he suggested preparations for nuclear tests were underway elsewhere.

“If a country with the capability makes the erroneous decision to conduct nuclear tests, and Washington is clearly in our focus, then we will retaliate immediately,” he said.

This story is breaking. More to follow.