MOSCOW (Reuters) - Moscow will limit the scope of U.S. military observation flights over Russia from Jan. 1 next year in retaliation for U.S. curbs on similar Russian flights over the United States, the RIA news agency reported on Wednesday.

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 U.S. observation flights over its heavily militarized Baltic exclave of Kaliningrad.

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 U.S. measures from Jan. 1 and limit the territory which U.S. observations flights can fly over.