MOSCOW, September 8 (RIA Novosti) - Russia and Belarus are starting a large-scale military exercise involving about 12,500 service personnel and up to 200 items of military equipment and hardware, the Russian Defense Ministry said on Tuesday.

The drill, called Zapad (West) 2009, takes place in Russia and Belarus and will end on September 29.

"The plan for the exercises was developed jointly by the Russian and Belarusian Armed Forces General Staffs and is purely defensive," the ministry said, adding that tasks to be practiced include dealing with armed conflicts, natural and man-caused disasters and ensuring strategic deterrence as well as the security of the Russia-Belarus Union State.

The ex-Soviet neighbors announced plans in the late 1990s to form a union state in a bid to achieve greater political, economic and military integration, but the project has largely existed on paper.

The exercise will, among other things, rehearse interoperability within the framework of the Belarusian-Russian integrated air defense system, which the two countries agreed to establish recently.

Russia is represented by the Moscow Military District units, Ground Forces, Air Force, Air Defense Forces, Airborne Troops and Baltic Fleet naval task forces, and Belarus by operational command units, Interior Ministry, Emergencies Ministry and State Security Committee troops.

The exercise will involve 5,000-6,000 Russian servicemen and 7,000-8,000 Belarusian servicemen, as well as up to 40 aircraft.