Iran Shuts Down Key Centrifuges

TEHRAN, Iran (AP) — A landmark deal aimed at easing concerns over Iran's nuclear program is taking effect.

Iran today unplugged banks of centrifuges that were involved in its most sensitive uranium enrichment work.

The United States and the European Union quickly responding by lifting some economic sanctions. The White House says today's actions mark "the first time in nearly a decade that Iran has verifiably enacted measures to halt progress on its nuclear program."

The moves also start a six-month clock for Iran and world powers to negotiate a final agreement aimed at ensuring Iran cannot build a nuclear weapon.

Tehran denies its nuclear program is intended to produce a bomb. The deal allows Iran to continue uranium enrichment at low levels, sufficient to fuel an electricity-generating reactor.

Meanwhile, White House spokesman Jay Carney says the U.S. and other world powers will continue aggressive enforcement of sanctions as negotiations over a final deal proceed. Those talks are expected to start next month.