LAUSANNE, Switzerland — Envoys from the six global powers that have spent 18 months trying to negotiate a nuclear deal with Iran hope to complete an outline as early as Sunday, two days before the March 31 deadline, according to a top diplomat.

British Foreign Secretary Philip Hammond, speaking to reporters Friday in Washington, said diplomats hope to reach a preliminary deal “over the next 48 hours” but will keep working if they don’t.

Josh Earnest, the White House press secretary, said it was “possible” the negotiators would need until early next week to complete the framework.

Negotiating teams led by Secretary of State John F. Kerry and Iranian Foreign Minister Mohammad Javad Zarif have faced off across a table several times since Thursday morning.

Hammond is expected to arrive Saturday, along with French Foreign Minister Laurent Fabius. The Russian, Chinese and German foreign ministers are expected to fly in Saturday or Sunday.

The group would want to join the final hours of the historic talks, to give their blessing to any final deal and to appear together for an official announcement that could head off a nuclear arms race in the Middle East.

A senior State Department official said Friday that the last two days of talks between Kerry and Zarif “have been tough and very serious.”

The two sides also remain at odds over what form their outline will take.

U.S. officials say they want to provide details to the public to allow them to judge the merits of the preliminary deal.

Iranian officials are wary of disclosing too much until all the details are negotiated. They have been reluctant to put what they call a “political understanding” in a written document.

Copy the Story Link