"Today, the US - together with our close allies and partners - took an important first step toward a comprehensive solution that addresses our concerns with the Islamic Republic of Iran's nuclear programme," Obama said at the White House after the deal in this regard was reached in Geneva.
"The first step that we've taken today marks the most significant and tangible progress that we've made with Iran since I took office," said the US President.
Under the deal, Iran has agreed to halt all enrichment above five per cent and dismantle the technical connections required to enrich above five per cent.
The deal was reached after US Secretary of State John Kerry flew into Geneva and met his counterparts of other P5+1 countries, which in addition to the US includes France, Britain, China, Russia and Germany.
The deal, Obama said, would help his administration reach the goal of preventing Iran from acquiring nuclear weapons.
"Today, that diplomacy opened up a new path toward a world that is more secure -- a future in which we can verify that Iran's nuclear programme is peaceful and that it cannot build a nuclear weapon," he said.
"While today's announcement is just a first step, it achieves a great deal. For the first time in nearly a decade, we have halted the progress of the Iranian nuclear programme, and key parts of the programme will be rolled back," he said.
Iran has committed to halting certain levels of enrichment and neutralising part of its stockpiles, he said, adding Tehran cannot use its next-generation centrifuges, which are used for enriching uranium.
"Iran cannot install or start up new centrifuges, and its production of centrifuges will be limited. Iran will halt work at its plutonium reactor. And new inspections will provide extensive access to Iran?s nuclear facilities and allow the international community to verify whether Iran is keeping its commitments," Obama said.
"These are substantial limitations which will help prevent Iran from building a nuclear weapon. Simply put, they cut off Iran's most likely paths to a bomb," he said, adding that the move will create time and space over the next six months for more negotiations to fully address comprehensive concerns about the Iranian programme.