Belarusian First Deputy Defense Minister Oleg Belokonev has revealed some details related to the Russian military deployments that are part of the upcoming Zapad 2017 military drills in the Baltic region. He said around 10,200 Belarusian and Russian military personnel would be deployed to Belarus for the large-scale exercise. Belokonev said that the exercises will also involve 370 armored fighting vehicles — including about 140 main battle tanks — 40 combat aircraft and helicopters, and up to 150 artillery units and multiple-launch rocket systems. Belarus is making a point to be transparent about the numbers of troops and assets deployed because under the Vienna Document — as promulgated by the Organization for Security and Co-operation in Europe — foreign observation is required if troop levels exceed 13,000. While it's estimated that around 12,700 troops will be deployed overall, that number isn't set in stone.