MOSCOW, May 31 (RIA Novosti) - Russia's Ground Forces will conduct over 140 operational and tactical field exercises in the second half of this year, an aide to the Ground Forces commander said on Saturday.

"For the first time in 15 years three military districts - Moscow, Far Eastern and Volga-Urals - will hold large-scale operational level exercises," Col. Igor Konashenkov said, adding that North Caucasus and Volga-Urals military districts will also conduct two divisional level drills.

He said the exercises will focus on practicing interoperability and combat effectiveness of the troops under a comprehensive combat training program.

Russia's Ground Forces are placed in six military districts of the country and total about 400,000 personnel, according to some estimates.

This branch of the Armed Forces deploys over 22,800 main battle tanks, over 15,000 infantry fighting vehicles, about 10,000 armored personnel carriers and almost 20,000 artillery pieces including self-propelled artillery.