MOSCOW—Russia is creating three new divisions to counter the North Atlantic Treaty Organization’s planned expansion along its eastern flank, Defense Minister Sergei Shoigu said Wednesday, in a move that comes amid rising tensions in the region.

Moscow has threatened it will respond to NATO plans to boost its troops’ presence along its border with Russia. Western officials said last week the alliance will send four battalions—about 4,000 troops—to Poland and the ex-Soviet Baltic countries.

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