The Trump administration on Thursday announced that it is withdrawing the United States from the Open Skies Treaty, an international agreement of nearly three dozen member nations that allows countries to fly unmanned surveillance flights over each other’s airspaces.

President Trump on Thursday told reporters that Russia had not adhered to the terms of the agreement. The Russian government has reportedly restricted flight paths over certain parts of its country in violation of the treaty.

The treaty has been signed by a total of 34 separate countries. Upon its adoption it “established a regime of unarmed observation flights over the territories of State Parties” and denoted “quotas for observation flights, the notification of points of entry, the technical details and inspection for sensors.”

Member states were permitted to explore “the land, including islands, and internal and territorial waters, over which a State Party exercises sovereignty,” and were obliged to open up their own lands for equal inspection.

Rep. Senator Tom Cotton, of Arkansas, praised the decision, writing on his website that the agreement was “dysfunctional and broken.”

“For Mr. Putin, the treaty was just another scheme to snatch a military and surveillance advantage over the U.S. and NATO. Further, the treaty was technically defunct, as outdated and irrelevant as the VHS recorder or cassette deck,” he said.

The decision to withdraw received some pushback from European military officials this month; they claimed that backing out of the treaty would endanger international arms agreements and undermine global security.