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Iran nuclear deal to take effect on Jan. 20

TEHRAN — Iran's interim nuclear deal with the world's major powers is scheduled to begin on January 20, officials with Iran and the European Union said Sunday.

"Capitals have confirmed the result of the talks in Geneva ... the Geneva deal will be implemented from January 20," Marzieh Afkham, a spokeswoman for the Iranian Foreign Ministry told reporters in Tehran, the semi-official Mehr news agency said.

The EU's foreign policy chief Catherine Ashton also confirmed the news in a statement on Sunday.

Ashton represents the six nations — the United States, Russia, China, France, Britain and Germany — in diplomatic contacts with Iran related to the nuclear standoff.

She said the sides would now ask the United Nations' nuclear watchdog to verify the deal's implementation.

"We will ask the IAEA (International Atomic Energy Agency) to undertake the necessary nuclear-related monitoring and verification activities," she said.

Under the November 24 agreement, Iran has promised to curb its most sensitive nuclear activities in return for some relief from Western economic sanctions.

Iran's deputy Foreign Minister Abbas Araghchi said on Iranian TV that the main sticking points of the deal had been resolved, and his country will receive $4.2 billion in frozen assets in return for diluting a cylinder of 20 percent enriched uranium every three weeks.

In a statement from the White House after the announcement Sunday, U.S. President Barack Obama cheered the news.

"With today's agreement, we have made concrete progress," he said, "I welcome this important step forward, and we will now focus on the critical work of pursuing a comprehensive resolution that addresses our concerns over Iran's nuclear program."

Obama added, "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."

U.S. Secretary of State John Kerry said the next stage in talks with Iran on its nuclear program would be "very difficult" after an announcement on Sunday that an interim deal with world powers, designed to create space to reach a comprehensive pact, would take effect on January 20.

"The negotiations will be very difficult," Kerry said at a news conference in Paris with his Qatari counterpart.

NBC News' Hasani Gittens and Reuters contributed to this report