Iran and six world powers signed an agreement implementing a plan that temporarily freezes Iran’s nuclear production.

The Joint Plan of Action, which was finalized and approved on Sunday, will go into effect on Jan. 20.

Under the plan first agreed to in November, Iran will freeze most of its nuclear enrichment capability, including not installing or starting up additional centrifuges or using next-generation centrifuges.

In return, the United States and five other world powers — Germany, Russia, England, France and China — will provide Iran with some economic sanctions relief. Iran also will allow new and more frequent inspections of its nuclear sites.

“Taken together, these and other steps will advance our goal of preventing Iran from obtaining a nuclear weapon,” President Obama said in a statement released Sunday by the White House.

The statement said the focus will turn to what Obama called “the critical work of pursuing a comprehensive resolution that addresses our concerns over Iran’s nuclear program.”

“I have no illusions about how hard it will be to achieve this objective, but for the sake of our national security and the peace and security of the world, now is the time to give diplomacy a chance to succeed,” he said.