In this image made from video provided by Russian Defense Ministry Press Service on Thursday, May 21, 2026, Russian military personnel take part in drills of Russia's nuclear forces. (Russian Defense Ministry Press Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Thursday, May 21, 2026, A Borel-class nuclear submarine is seen during drills of Russia's nuclear forces. (Russian Defense Ministry Press Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Thursday, May 21, 2026, A Yars intercontinental ballistic missile is test-fired during drills of Russia's nuclear forces. (Russian Defense Ministry Press Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Thursday, May 21, 2026, A Yars intercontinental ballistic missile is seen during drills of Russia's nuclear forces in Belarus. (Russian Defense Ministry Press Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Wednesday, May 20, 2026, Russian servicemen prepare to launch an interceptor drone for an action in an undisclosed location in Ukraine. (Russian Defense Ministry Press Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Wednesday, May 20, 2026, Russian servicemen carry an interceptor drone to launch for an action in an undisclosed location in Ukraine. (Russian Defense Ministry Press Service via AP)

In this photo provided by the Ukrainian Emergency Service, firefighters put out a fire in a building following a Russian air attack in Dnipropetrovsk region, Ukraine, Thursday, May 21, 2026. (Ukrainian Emergency Service via AP)

In this image made from video provided by Russian Defense Ministry Press Service on Thursday, May 21, 2026, Russian navy personnel is seen during drills of Russia's nuclear forces. (Russian Defense Ministry Press Service via AP)