The United States has accused Russia of flouting the Open Skies Treaty, an agreement designed to build confidence between the countries’ militaries which entered into force in 2002, and said it plans to take measures against Moscow.

The Wall Street Journal newspaper reported in September that this would include restricting Russian military flights over American territory in response to what it said was Moscow preventing US observation flights over its heavily militarized Baltic exclave of Kaliningrad, Reuters reported.

The United States is reported to have been keen to restrict Russian flights over Alaska and Hawaii as well as limiting the distance of Russian observation flights.

RIA on Wednesday cited Georgy Borisenko, a senior foreign ministry official, as saying Moscow would take reciprocal steps to respond to the new US measures from Jan. 1 and limit the territory which US observations flights can fly over.