The United States has announced plans to send a KC-135 refueling tanker and six additional F-15s to the Baltics to shore up NATO‘s Air Policing mission in the region.

According to Air Force Times, the move means that there will be a total of 11 on-call aircraft which the U.S. provides to identify and respond to violations of Baltic airspace. The news comes amid tension between the Ukraine and Russia in the Crimean Peninsula.

There are over a dozen countries, including the United States, have rotated aircraft in and out of the region for roughly a decade. As Air Force Times reports, the first four U.S. F-15s arrived on Jan. 1. Their rotation will end on April 30.

Read more: http://www.airforcetimes.com/article/20140305/NEWS08/303050034/U-S-sending-F-15s-tanker-patrol-Baltic-airspace