The U.S. and five world powers have reached a tentative agreement with Iran over its nuclear program, a landmark deal that brings a close to over a year of intense negotiations and economic restrictions on Iran.

On the Iranian side, the country has agreed to not produce enriched uranium among other restrictions to prevent the production of a bomb, while the U.S., U.K., Germany, Russia, France and China have agreed to lift economic sanctions immediately, ABC News reported.

"Today we have taken a decisive step," Federica Mogherini, the European Union's High Representative, said Thursday in Switzerland. "We have reached solutions on key parameters of a joint comprehensive plan of action."

Iranian Foreign Minister Mohammad Javad Zarif praised the framework reached after eight-days of nonstop negotiations.

"We have stopped a cycle that is not in the interest of anybody," Zarif said, according to The New York Times.

Talks began in late 2013 when Iran and P5+1, comprised of the U.S. and the other five world powers, installed a temporary agreement to allow for talks to commence while Iran's nuclear enrichment program was suspended for inspection, according to ABC News.

In the new agreement, Iran agreed to not enrich uranium above 3.37 percent, not build any new facilities and reduce the country's stockpile of 10,000 kilograms of low-enriched uranium to 300 kilograms- all for the next 15 years.

Iran's nuclear facility at Fordo is to be converted into a center for technology and physics, ABC News reported. The Iranians have also agreed to stop using a water reactor in Arak to make weapons-grade plutonium.

In short, according to U.S. Secretary of State John Kerry, every pathway to build a bomb has been cut off, The NY Times reported. In exchange, the U.S. and EU will lift economic sanctions once a final, official deal is drafted in June.

President Barack Obama called the agreement "an historic understanding with Iran."

"This has been a long time coming," President Barack Obama said back in Washington D.C.

But Western officials stressed the repercussions would be swift if Iran were to break the deal.  

"If Iran cheats, the world will know it. If we see something suspicious, we will inspect it," Obama said. "With this deal, Iran will face more inspections than any other country in the world."