Poland's defense minister says a major exercise conducted by NATO members and partner nations in Poland successfully demonstrated joint capabilities of defending the region from threat rising in the east.

Antoni Macierewicz and foreign diplomats on Thursday watched the conclusion of the exercise, dubbed Anakonda-16, the biggest to be held on Polish soil in 27 years of democracy. It is taking place at a time of heightened security concerns in the region.

The massive land and air drill involved an armored combat group, supported by the artillery and air forces, on the Drawsko Pomorskie test range in northwestern Poland.

Anakonda-16 involved some 31,000 troops from Poland, the U.S. and 17 other NATO member nations and from five partner nations. A closing ceremony will be held on Friday in Warsaw.