The Armed Forces of Russia launched a four-day snap drill to test combat readiness of the air and air defense units in the country's Central Military District (CMD), the Defense Ministry said Monday.

About 12,000 troops, 250 aircraft and 689 pieces of military equipment are involved in the exercises, the ministry said in a statement.

"The inspection aims to assess the CMD Air and Air Defense Forces' capability to perform the task of destroying an aerial enemy in cooperation with reinforcement troops," the Interfax news agency quoted a ministry spokesperson as saying.

Russian President Vladimir Putin ordered the military earlier this year to conduct a series of unexpected drills to test combat readiness of the armed forces.

The Russian military staged a round of large-scale surprise exercises in March amid increasing NATO military presence near the Russian borders.