Iran nuclear talks to go on till April 2

Lausanne: Negotiations over the Iranian nuclear programme has been extended for the second time after the world powers and Iran missed the March 31 deadline for a preliminary accord. The talks will now continue into Thursday.

US state department spokesperson Marie Harf said progress had been made in the talks, adding that US Secretary of State John Kerry would be staying “until at least Thursday morning”, The Washington Post reported on Wednesday.

“We continue to make progress, but have not reached a political understanding,” Harf said.

In Washington, White House spokesman Josh Earnest said the talks continued to be productive, but that there were still unresolved details. He reiterated that the US would walk away from the negotiations if necessary.

The negotiations had earlier been extended until Wednesday after the original deadline was missed.

However, the talks appeared to be on a shaky ground, as the White House said it had not yet received commitments from Iran about its nuclear programme on Wednesday, and Iran's Foreign Minister and chief negotiator, Mohammed Javad Zarif, described negotiations with the West as “always problematic”.

Zarif noted: "I've always said that an agreement and pressure do not go together; they are mutually exclusive.

"So our friends need to decide whether they want to be with Iran based on respect or whether they want to continue based on pressure. They have tested the other one. It is high time to test this one."

Though the talks did not appear to be on the verge of collapse, German Foreign Minister Frank-Walter Steinmeier said that was a possibility.

He said new proposals would be considered, though Iran and the world powers were still far apart.

When asked if the talks could collapse, Steinmeier told German reporters: “Naturally. Whoever negotiates has to accept the risk of collapse...”

The German foreign minister said he would reassess in the morning whether to stay or return home, depending on how the talks went on Wednesday night, adding that it was up to Iran to present counterproposals.

The departure of three of the five foreign ministers negotiating alongside Kerry left only the British and German foreign ministers and the European Union (EU) foreign policy chief Federica Mogherini beside him at the negotiating table on Wednesday.

While the meaning of their departure was unclear, there was a sense that the negotiators were struggling to salvage the talks.

In Paris, French Foreign Minister Laurent Fabius suggested that no agreement is imminent.

The March 31 deadline was set three months back as a mechanism to determine whether there was enough political will to reach a final accord by the end of June, when an interim agreement temporarily limiting Iran's nuclear activities would expire.

The issues the negotiators have been struggling to resolve include the pace at which the UN sanctions would be lifted, restrictions on research and development related to new types of centrifuges, and the length of the agreement.

A deal will impose restrictions on Iran's nuclear programme in return for a lifting of crippling sanctions imposed on Tehran.