WASHINGTON (AP) — The United States will begin easing economic sanctions on Iran after it began shutting down its most sensitive nuclear work on Monday, the White House said.

Iran’s move was part of a landmark deal struck late last year with the U.S., five other world powers and the European Union to ease concerns over Tehran’s nuclear program and provide for the partial removal of some of the economic sanctions that have crippled the Iranian economy. Iran has insisted that its nuclear program was for peaceful purposes only.