LAUSANNE, Switzerland -- The basis for an agreement for a peaceful Iranian nuclear program and a lifting of sanctions against that nation has been reached, European Union foreign policy chief Federica Mogherini announced Thursday.
"We have reached solutions on key parameters of a joint comprehensive plan of action," she said.
A "broad political agreement with some specifics" was announced in a joint statement from the parties involved in the talks. The agreement puts significant curbs on Iran's nuclear program but leaves much of it intact.
Iran's enrichment capacity and stockpile would be limited, and Iran's sole enrichment facility would be at the Natanz nuclear facility, Mogherini said. Other nuclear facilities would be converted for other uses, she said.
Under the agreement, the nuclear facility at Fordow would be converted to a nuclear physics and technology center, and the facility at Arak would be redesigned as a heavy-water research reactor that will not produce weapons-grade plutonium.
The European Union would terminate all nuclear-related economic and financial sanctions against Iran, and the United States would do the same once Iran's implementation of the agreement is confirmed, according to announcements of the deal.
The United Nations would terminate all previous resolutions sanctioning Iran and would incorporate other restrictions for an agreed-upon period.
The preliminary agreement will not put an end to the country's enrichment activities, Iranian Foreign Minister Javad Zarif said.
Iran will, however, abide by the agreement, which would limit enrichment activities to one location, he said.
"None of those measures include closing any of our facilities. The proud people of Iran would never accept that," he said.
"If fully implemented, this will prevent it from obtaining a nuclear weapon," President Barack Obama said. "It's a good deal, a deal that meets our core objectives."
Obama said Iran will not stockpile materials it needs to build a nuclear weapon.
"If Iran cheats, the world will know it," he said. "If we are suspicious, we will inspect it."
U.S. Secretary of State John Kerry sent a tweet saying "parameters to resolve major issues" have been reached.
"Found solutions," Zarif tweeted. "Ready to start drafting immediately."
"Solutions on key parameters" reached, Iranian President Hassan Rouhani said on Twitter. The European Union's foreign policy chief, Federica Mogherini, tweeted, "Good news," regarding the talks.
The goal had been to agree on a framework for a future final nuclear agreement by Tuesday. The talks stretched well past the original deadline.
The statement marks the end of a round of talks that started last week.
Earlier Thursday, as Zarif was walking back to the hotel where the negotiations were being held, he told reporters that a statement was in the works.
The talks, aimed at reaching a preliminary political deal on Iran's nuclear program, blew past their initial, self-imposed deadline of late Tuesday as Iranian and U.S. negotiators struggled to find compromises on key issues.
But the negotiators have doggedly continued their work in Lausanne, trying to overcome decades of mistrust between Tehran and Washington.
The mutual mistrust has been a serious problem in the talks, Zarif said.
"I believe respect is something that needs to be exercised in practice and in deeds, and I hope that everyone is engaging in that in mutual respect," he said.