Russian leaders insist their soldiers have no plans to invade Ukraine. But their troops raised alarms on Wednesday as they prepared for a military exercise with their closest ally, Belarus.

Troops will spend 11 days in the Brest region of Belarus in an exercise they call Union Resolve. They will practice using air defense and other missile systems. Fighter pilots will train in intercepting targets.

A Kremlin spokesperson said the scope of the drills is larger than before because the situation is "far more tense." But Dmitry Peskov said the troops will return to their bases once they are done.

Ukrainian defense officials have announced they are holding their own drills over the same period. They will practice using anti-tank missiles and drones they just got from other countries.