2nd LD: Obama says "historic" preliminary deal will prevent Iran from obtaining nuclear bomb

President Barack Obama on Thursday hailed the "historic" framework deal reached with Iran, saying it meets U.S. "core objectives" and will prevent the Islamic Republic from obtaining a nuclear bomb.

"Today, the United States, together with our allies and partners, has reached a historic understanding with Iran, which, if fully implemented, will prevent it from obtaining a nuclear weapons," the president said in a statement delivered in the White House Rose Garden.

Foreign ministers of the U.S. and other major powers -- Britain, France, Russia, China plus Germany -- agreed Thursday on parameters to resolve major issues on Iran's nuclear program, following eight-day-long intense negotiations in the Swiss city of Lausanne, with a view to sealing a final comprehensive pact by the end of June.

Obama called the framework deal a "good" one that "meets our core objectives."

Under the parameters unveiled by the Obama administration, Iran agrees to reduce its installed centrifuges to 6,104 from some 19, 000, suspend the enrichment of uranium over 3.67 percent for at least 15 years and cut its stockpiled low-enriched uranium from about 10,000 kilograms to 300 kilograms for 15 years.

In addition, Iran allows regular access to all of its nuclear facilities for inspections by the International Atomic Energy Agency, and agrees to redesign and rebuild a heavy water research reactor in Arak that will not produce weapons-grade plutonium.

In return, the U.S. and the European Union will suspend sanctions on Tehran, along with lifting of all UN Security Council 's past sanction resolutions.

The framework pact also sees Iran's breakout time, time taken to enrich enough weapons-grade uranium or plutonium for a nuclear weapon, being extended to at least one year from the estimated two to three months now for a duration of at least ten years. Endite