Date set to begin Iran nuclear deal

US officials Sunday welcomed the report that Iran and six world powers have agreed on how to implement a deal involving Iran’s nuclear capabilities.

The agreement, which came together in November, will temporarily freeze Iran’s nuclear program, in return for which Iran will gain access to $4.2 billion in restricted assets, released in regular installments throughout the six months and easing the impact of international economic sanctions.

As announced Sunday, first in Tehran and then in other world capitals, the deal now is set to begin being implemented Jan. 20.

Under the November agreement, Iran agreed to limit its uranium enrichment to 5 percent – the grade commonly used to power reactors. The deal also commits Iran to stop producing 20 percent enriched uranium – which is only a technical step away from weapons-grade material – and to neutralize its 20 percent stockpile.

In exchange, economic sanctions Iran faces would be eased for a period of six months. During that time, Britain, China, France, Germany, Russia, and the United States would continue negotiations with Iran on a permanent deal.

Iran's semi-official ISNA news agency reported Sunday that under the terms of the deal, Iran will guarantee that it won't try to attain nuclear arms "under any circumstance."

In a statement Sunday, President Obama said he has “no illusions about how hard it will be to achieve this objective.”

But he noted that the agreement “marks the first time in a decade that the Islamic Republic of Iran has agreed to specific actions that halt progress on its nuclear program and roll back key parts of the program.” This includes not installing or starting up additional centrifuges or using next-generation centrifuges, which are used to enrich uranium.

In a separate statement, Secretary of State John Kerry said further negotiations "represent the best chance we have to resolve this critical national security issue peacefully, and durably."

Secretary Kerry also touched on a major political challenge for the Obama administration going forward:

“I very much appreciate Congress’ critical role in imposing the sanctions that brought Iran to the table, but I feel just as strongly that now is not the time to impose additional sanctions that could threaten the entire negotiating process,” Kerry said. “Now is not the time for politics.”

Fifty-nine senators, including16 Democrats are sponsoring a bill in support of a new round of sanctions, including further cuts in Iran's oil exports. The House overwhelming passed a similar bill last summer.

Writing in the Washington Post last week, Sen. Robert Menendez (D) of New Jersey, who chairs the Senate Foreign Relations Committee, argued that the threat of increasing economic pressure needs to be kept on Iran in the form of what supporters have named the “Nuclear Weapons Free Iran Act.”

“It supports continued negotiations, gives the administration a year of flexibility to secure a comprehensive agreement, respects the sanctions relief Iran is set to receive and prevents any new sanctions from taking effect while good-faith negotiations are underway,” Sen. Menendez wrote. “If the Iranians abide by their commitments, they’ll receive the economic relief they desperately want.”

But, he added, “Should Iran breach this agreement or fail to negotiate in good faith, the penalties it would face are severe. Nations would be required to further reduce their purchases of Iranian petroleum, and new sanctions would be applied against Iran’s mining, engineering and construction sectors.”

Making plain the administration’s position here, Obama said in his statement Sunday, “I will veto any legislation enacting new sanctions during the negotiation.”

This report includes material from the Associated Press.