President Vladimir Putin on Sunday ordered Russian nuclear deterrent forces to be placed on high alert, due to what he described as “aggressive statements” by Western adversaries.

During a meeting with top Russian officials, Putin directed the Russian defense minister and the chief of the military’s General Staff to put the nuclear deterrent forces in a “special regime of combat duty.”

“Western countries aren’t only taking unfriendly actions against our country in the economic sphere, but top officials from leading NATO members made aggressive statements regarding our country,” Putin said in televised remarks

The instruction means Putin has ordered Russia’s nuclear weapons prepared for heighted readiness to launch, raising the possibility the Russia-Ukraine war could escalate to a nuclear war.

The startling measure came as street fighting broke out in Ukraine’s second-largest city as part of advances that appeared to be a