The United States and other world powers have reached a deal with Iran. Diplomats say the deal will limit Iran's nuclear activities in exchange for an easing of economic restrictions on the country.

　　In Washington, President Barack Obama praised the agreement. He said that, "this deal demonstrated that American diplomacy can bring about real and meaningful change."

　　"Today because America negotiated from a position of strength and principle we have stopped the spread of nuclear weapons in this region. Because of this deal, the international community will be able to verify that the Islamic Republic of Iran will not develop a nuclear weapon."

　　He spoke after the deal was announced Tuesday in Vienna. Negotiators spent weeks finalizing details of the agreement.

　　Reaction in Vienna

　　European Union foreign policy chief Federica Mogherini spoke to reporters in Vienna. She described the agreement as complex, detailed and technical. But she said it also was a "sign of hope" for the world.

　　"We know that this agreement will be subject to intense scrutiny. But what we are announcing today is not only as deal, it is a good deal. And a good deal for all sides and the wider international community. This agreement opens new possibilities and a way forward to end a crisis that has lasted for more than 10 years."

　　After her comments, Iranian foreign minister Javad Zarif spoke to the same reporters in Persian. He said he was repeating what the EU official had just said in English.

　　Mr. Zarif called the deal a "win-win" for both Iran and the group known as P5+1. They are Britain, China, France, Russia, the United States and Germany.

　　The deal

　　The deal will limit Iran's possible development of nuclear weapons while enabling the country to keep its civil nuclear program. U.S. officials say this will be done, in part, by reducing the number of Iran's modern centrifuges. These machines use centrifugal force to separate substances or parts of substances.

　　A main issue throughout the talks was international inspections of Iran's nuclear areas. This was solved with the creation of a process that lets United Nations inspectors push for entry, but gives Iran the right to not immediately agree. Instead, Iran will have the right to dispute the UN request through negotiations.

　　The deal continues an international ban on conventional arm sales to Iran for five more years, and a missile ban for eight years. But the bans could end earlier if the UN's nuclear agency finds Iran has undone any current work toward nuclear weapons. The Iranian government has repeatedly denied such work.

　　In exchange, the P5+1 countries agreed to lift economic sanctions on Iran as soon as it honors the requirements of the nuclear deal.

　　Possible barriers in the future

　　The agreement represents a historic compromise after a 12-year dispute between Iran and other countries. At times, the disagreement threatened to incite a new conflict in the Middle East.

　　Israeli Prime Minister Benjamin Netanyahu called the nuclear deal a "stunning, historic mistake." He declared his country is "not bound by the international nuclear pact with Iran" and that Israel has the right to defend itself.

　　Israel is looking to pressure the U.S. Congress, where Republican lawmakers are opposing the deal.

　　Bob Corker is chairman of the Senate Foreign Relations Committee. He does not believe the deal will prevent Iran from "obtaining a nuclear weapon."

　　Senator Corker said Congress will need to study the deal and decide whether supporting it is worth lifting sanctions that took years to establish.

　　To answer his critics at home and overseas, President Obama said,

　　"I am confident that this deal will meet the national security interest of the United States and our allies. So I will veto any legislation that prevents the successful implementation of this deal."

　　I'm Anne Ball.

　　This story was based on reports from VOA's News Division. George Grow adapted them for Learning English. Hai Do was the editor.