Russia says it will form new military divisions to be stationed along the country's borders with Europe to counter a planned NATO buildup.

Russian Defense Minister Sergei Shoigu said Wednesday that two new divisions would be formed along the western border and one along the southern border by the end of the year.

Shoigu gave no specifics about the number of additional troops to be deployed.

U.S. Defense Secretary Ash Carter said Monday that the NATO alliance was considering establishing a continuous rotation of up to 4,000 troops in the Baltic states and possibly Poland, reflecting deepening worry in the West about Russian military assertiveness.

Carter said this would be separate from a U.S. decision to send a U.S. armored brigade of about 4,200 troops to Eastern Europe next February.