BRUSSELS — The biggest build-up of NATO forces since the Cold War is set to be deployed next year on Russia’s European borders.

According to Reuters, American and British military personnel are being sent to join NATO forces in eastern Europe in 2017 after a series of high-profile Russian military maneuvers in the region.

The British Ministry of Defense said in a news release on its website that Royal Air Force Typhoon aircraft will be deployed to Romania for four months in 2017. In addition, around 800 British military personnel will be sent to Estonia. This is said to likely include infantry, tanks, armored fighting vehicles tactical drones.

The U.S. Department of Defense said in a news release that it will send 900 troops to Poland. According to Reuters, another American force made up of tanks will be deployed to maneuver across eastern Europe.

When assembled, the NATO force is expected to consist of 4,000 personnel that will be backed a 40,000-strong rapid reaction force.

The forces are set to be in place by the summer of 2017.