(MOSCOW) — Russian politicians accused the United States on Friday of undermining global security by ending compliance with a nuclear arms treaty, while NATO said Russia was at fault for the pact’s demise and European countries watched with dismay.

The U.S. announced it would stop observing the Intermediate-Range Nuclear Forces treaty as of Saturday and would withdraw within six months from the pact, a cornerstone of international security since 1987.

The treaty signed by the United States and the Soviet Union bans the development, deployment and testing of land-based nuclear weapons with a range of 500 to 5,500 kilometers (310-3400 miles). Moscow and Washington have for years traded claims of the other party being in violation.