Iran, global powers reach nuclear deal: UpdateOREANDA-NEWS. Iran reached an historic but tentative agreement with the US and other global powers today that would limit Tehran's nuclear activities in exchange for an easing of sanctions that have severely curtailed oil exports from Opec's third largest producer.

In what could prove a watershed moment in relations between Iran and the international community, the negotiators unveiled a framework for a final deal under which the US and EU – over time - would suspend nuclear-related economic and financial sanctions.

Sanctions on Iran's oil sector are unlikely to be lifted before late this year, at the earliest.

"We have taken a decisive step," EU high representative for foreign affairs Federica Mogherini said, reading from the text of the agreement hammered out after an all-night negotiating session. Mogherini was joined onstage in Lausanne, Switzerland, by Iranian foreign minister Mohammad Javad Zarif, who read the same text in Farsi.

The agreement between Iran and the P5 + 1 negotiating partners – the US, UK, France, Russia, China and Germany - will serve as a framework to achieve a comprehensive accord by 30 June.

President Barack Obama called the accord "our best option by far" for ensuring Iran does not obtain a nuclear weapon. "This deal is not based on trust. It is based on unprecedented verification," Obama said in address from the White House's Rose Garden. Iranian President Hassan Rohani tweeted that the agreement features "solutions on key parameters of Iran nuclear case," with "drafting to start immediately."

The agreement would limit Iran's domestic enrichment capacity for 10 years and will ensure a "breakout time" to make a weapon of at least a year. And Tehran will be barred from building any enrichment facilities for 15 years.

In exchange, the EU is expected to lift its embargo on Iranian oil, and the US will not threaten to impose sanctions on the banks of countries that purchase Iranian oil or fail to reduce their imports significantly. Six countries now buy oil from Iran – China, India, Turkey, South Korea, Japan and Taiwan. Iran does not gain access to the proceeds of those sales directly but must, instead, engage in bilateral trade with those countries.

The US and EU sanctions will be suspended after UN nuclear watchdog the IAEA has verified that Iran taken all of its key nuclear-related steps promised. The sanctions relief will be phased in "as Iran takes steps to adhere to the deal," Obama said. "If Iran violates the deal, sanctions can be snapped back into place."

Before any sanctions would be lifted, Iran will have to dismantle some of its centrifuges and the infrastructure associated with those centrifuges, work that could take four months to a year, secretary of state John Kerry said. And after the IAEA certifies that work has been completed "there would begin the phasing of the sanctions."

But the exact timing of sanctions relief "remains one of those issues that is going to be negotiated over the course of the next three months," Kerry said.

US energy research firm Clearview Energy Partners said the "high verification standard" and congressional suspicion of a deal "could back-load the resumption of crude sales into 2016, perhaps well into 2016."

Other US sanctions targeting Iran that were imposed in response to allegations of terrorist activity and human rights abuses will remain in place. Washington-based law firm and sanctions experts Ferrari & Associates noted that the sanctions provisions are the vaguest portions of the agreement.

Sanctions have taken their toll on the Iranian economy, reducing its exports to about 1.1mn b/d, not including condensate, less than half the 2.5mn b/d n 2012. Iran's oil output was 2.9mn b/d in February, up from 2.85mn b/d in January.

Oil minister Bijan Namdar Zanganeh has insisted that Iran can swiftly lift exports by 1mn b/d if US and the EU lift sanctions. Within two months of that point, Iran can restore production to 3.8mn b/d, Zanganeh told Argus in November

Obama now will have to sell the agreement to skeptics in the Middle East and on Capitol Hill.

He spoke today with Saudi Arabia's king Salman bin Abdel-Aziz and announced he will invite leaders from the Gulf Co-operation Council to the presidential retreat at Camp David this spring to discuss security cooperation.

He also planned to speak with Israeli prime minister Benjamin Netanyahu, who ignoring the obvious irritation of the White House addressed a joint session of the Republican-controlled Congress last month in a bid to scuttle a deal. Obama said "it is no secret that the Israeli prime minister and I do not agree about whether the US should move forward with a peaceful resolution to the Iranian issue."

Obama planned to discuss the agreement with leaders of the US House of Representatives and Senate today. "I will underscore that the issues at stake here are bigger than politics. These are matters of war and peace," Obama said.

The success of Obama's outreach will be tested on 14 April, when the Senate Foreign Relations Committee is scheduled to take up legislation that would enable Congress to review any deal before Obama can suspend or waive any congressionally-mandated sanctions.

Committee chairman Bob Corker (R-Tennessee) reacted cautiously to the agreement. "It is important that we wait to see the specific details of today's announcement," Corker said. But Corker said "there is growing bipartisan support for congressional review of the nuclear deal," and he expects strong support for the measure.

Obama has threatened to veto any such legislation, but proponents are working to collect enough votes to be able to override a presidential veto.

In trying to set the parameters of the debate with its explanation of the agreement, the US administration officials managed to irritate their Iranian counterparts. "The solutions are good for all, as they stand," Zarif tweeted. "There is no need to spin using ‘fact sheets' so early on."