KYIV, Ukraine (AP) — President Vladimir Putin ordered Russian nuclear deterrent forces put on high alert Sunday amid tensions with the West over his invasion of Ukraine.

Speaking at a meeting with his top officials, Putin asserted that leading NATO powers had made “aggressive statements” along with the West imposing hard-hitting financial sanctions against Russia, including the president himself.

The alert means Putin has ordered Russia’s nuclear weapons prepared for increased readiness to launch. He told 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 comments.