The Air Force has deployed six F-15C Eagle fighter jets to Iceland to conduct an air surveillance mission to support the NATO alliance.

The F-15Cs from the Louisiana and Florida Air National Guard, about 280 support airmen and equipment from the 125th Fighter Wing at Jacksonville Air National Guard Base, Florida, arrived Wednesday in Keflavik, Iceland, U.S. European Command said in a release Thursday. The airmen and planes are deploying as the 159th Expeditionary Fighter Squadron.

The airmen will conduct aerial training during the deployment, including refueling with a KC-135 Stratotanker from the 931st Air Refueling Wing from McConnell Air Force Base in Kansas and a KC-10 from the 514th Air Mobility Wing from McGuire Air Force Base in New Jersey, the release said.

EUCOM said the United States has conducted missions supporting NATO in Iceland each year since 2008, and is deploying the fighters to continue ”to demonstrate commitment to NATO and the security of Europe.”

The deployment comes at a time of increased tensions between Russia and NATO in Europe.