MOSCOW — President Vladimir Putin has put the Russian air force on high alert, the latest in a series of drills amid tensions with the West.

Defense Minister Sergei Shoigu said that the drills launched Tuesday will check the air force's readiness and its ability to repel an enemy aggression.

Shoigu told military officials that special emphasis will be given to practicing the deployment of air defense systems.

The maneuvers are the latest in a steady series of war games intended to strengthen the troops' readiness. Despite Russia's economic downturn, the Kremlin has continued to spend big on military training and weapons modernization amid tensions with the West over the Ukrainian crisis.