Iran and the P5+1 group of world powers (the United States, United Kingdom, Germany, France, Russia and China, facilitated by the European Union) reached a breakthrough Thursday in negotiations aimed at curbing Iran’s nuclear programs. The framework for an agreement emerged after eight days of dialogue in Switzerland, with months of previous talks having failed. If Iran adheres to the outlined restrictions and transparency measures on its nuclear aspirations, the Western powers will lift sanctions that have crippled the Iranian economy.

Iranian Foreign Minister Mohammad Javad Zarif, who met with international leaders in the city of Lausanne, called the draft agreement Thursday “a major step forward” and “a gain for all parties concerned.” But the deal has not yet been signed, and critical details must be worked out in the coming weeks for a finalized, comprehensive deal by the end of June. The U.S. made clear that no deal will be made if there is any backsliding on the Iranian side.

“Nothing is agreed to until everything is agreed to,” U.S. President Barack Obama said in a televised statement at the White House Thursday after the draft agreement was announced.

Obama said the finalized deal would “cut off every pathway Iranians could take” to develop nuclear weapons by slashing Iran’s enriched uranium stockpile by 98 percent and limiting enrichment activities to one location. Enriching uranium can be used to produce a nuclear weapon – an activity that Iran hid from the world for 18 years.

Zarif said none of these measures will include closing any of Iran’s facilities. Its Fordow facility will be converted into a nuclear, physics and technology research center, and its heavy water facility near Arak will be redesigned for peaceful purposes only, according to the deal, titled the Joint Comprehensive Plan of Action.

The deal would prohibit Iran from producing nuclear weapons but allow converting these programs into sources of research and power supply. In addition, Iran must comply with regular, robust inspections by the International Atomic Energy Agency to ensure the country is not violating any part of the agreement.

U.S. Secretary of State John Kerry said Thursday the restrictions on Iran’s nuclear capabilities would be implemented in phases. While some provisions would be put in place for 10, 15 or 25 years, others will “never expire,” he said. Iran will receive relief from sanctions once the deal is finalized, restrictions are in place and it verifiably abides by its commitments. But these financial and economic sanctions would “snap back” in place if Iranians failed to meet their end of the deal. “A final agreement would not rely on promises; rather it would rely on proof,” Kerry said during a press conference in Lausanne.

Both Obama and Kerry appeared certain a finalized agreement would produce a peaceful, diplomatic solution to a potentially dangerous global threat. “Under this arrangement, the international community will have confidence Iran’s nuclear program is exclusively peaceful if they adhere to the conditions,” Kerry said. “It is our best option by far.”