Obama: Iran nuke deal 'first step'

President Obama on Saturday hailed the historic deal between world powers and Iran to curb Tehran's nuclear program in exchange for limited sanctions relief.

"For the first time in nearly a decade, we have halted the progress of the Iranian nuclear program, and key parts of the program will be rolled back," Obama said from the White House.

The agreement, struck early Sunday in Geneva, includes a six-month program to limit how much the nation could enrich its uranium, making it more difficult for Iran to weaponize it. It would also cap Iran’s nuclear stockpile, and halt work on components of another nuclear reactor that could provide Iran with plutonium.

Those new limitations, combined with heightened oversight from outside inspectors, are all aimed at making it significantly more difficult for Iran to turn its existing nuclear capabilities into a nuclear bomb.

"Simply put, they cut off Iran's most likely paths to a bomb," Obama said.

In exchange, Iran would receive limited relief from global economic sanctions. The agreement sets the stage for broader talks about the state of Iran's nuclear program, buying time for diplomats to try and reach a longer-term solution.

Obama emphasized that the deal was just a "first step," but a critical one.

"This first step will create time and space over the next six months for more negotiations to fully address our comprehensive concerns about the Iranian program. And because of this agreement, Iran cannot use negotiations as cover to advance its program," he said.

He emphasized that the agreement also comes with a requirement for heightened oversight over Iran's nuclear programs, and that it was incumbent upon that nation to continue talks instead of looking for ways to skirt around the new agreement.

"In these negotiations, nothing is agreed to until everything is agreed to. The burden is on Iran to prove to the world that its nuclear program will be for exclusively peaceful purposes," he said.

“This is an opportunity that we had to seize. But we’re under no illusions,” a senior administration official added. “These are going to be tough negotiations.”

At the same time, the president urged his colleagues in Congress to hold off on pushing new sanctions on Iran, and to give time for this diplomatic process to work itself out. He warned that legislative efforts to impose new sanctions could "derail" that process. A senior administration official told reporters late Saturday night that the White House had already started reaching out to lawmakers to discuss the deal.

In all, senior administration officials say that the softening of sanctions against Iran will give Tehran at most $6 billion to $7 billion in new revenue, and that the pause in sanctions can be easily reversed.

Under the deal, the U.S. and its allies will suspend its efforts to further reduce Iran’s crude oil sales, not impose any more nuclear-related sanctions, and pause sanctions on the country’s automotive and petrochemical industries.

Facing quick criticism from Republicans, a senior administration official insisted Saturday night that Iran – currently mired in recession – would be worse off economically in six months, even with the new revenue. 

The president also noted the lingering concern from Israel and other allies in the Middle East, which have long been wary of any talks that permit Iran to continue possessing enriched nuclear material. He said those nations "have good reason to be skeptical about Iran's intentions."

Israeli Prime Minister Benjamin Netanyahu on Sunday denounced the deal, saying Israel would not be bound by the agreement.

“This agreement has made the world a much more dangerous place,” he said.

“Israel is not bound by this agreement,” Netanyahu added. “We will not allow Iran to have a nuclear weapons capability.”

A senior administration official said that Obama would likely speak on Sunday to Netanyahu, who has voiced deep skepticism about the deal as it materialized in recent days./p>

But the official insisted that the new agreement should help assuage some of Israel’s concerns – including by neutralizing Iran’s enriched uranium stockpile.

“Iran is not back in business,” another senior administration official said Saturday night. “And anyone who makes the mistake of thinking so will be met with some serious consequences.” 

Top-ranking diplomats, including Secretary of State John Kerry, huddled in Geneva Saturday to finalize talks that ran well into the evening and into Sunday morning there.

"We have reached an agreement," Iranian Foreign Minister Mohammad Javad Zarif announced on his Twitter feed shortly after the deal was announced.

This report was originally published at 12:00 a.m. and last updated at 7:34 a.m.