The U.S. and NATO announced today that they’re both sending more warplanes to Ukraine’s borders. The deployments are in response to Russia’s so-far bloodless invasion of Crimea.

The Pentagon said today that it’s sending additional F-16 fighters to Poland. The Air Force already has 12 F-16s at Lask air base for a long-planned training exercise.

The Defense Department hasn’t decided yet how many more F-16s will go to Poland—but the DoD did say the extra jets will come from units already in Europe. The Air Force has available F-16 units in Germany and Italy.

NATO announced today that E-3 radar planes will soon start flying over Poland and Romania. The alliance has 17 E-3s based in Germany and manned by airmen from across Europe and the U.S.