Iran Talks Drag into Day Eight after All-Nighter

Weary negotiators hoped Thursday to see the light at the end of the tunnel after talking until dawn, but midway through an eighth day were still haggling over the outlines of a deal curtailing Iran's nuclear program.

U.S. Secretary of State John Kerry and Iranian counterpart Mohammad Javad Zarif talked through the night, going line by line over their differences in a bid to agree a framework for an accord to cut back Iran's nuclear ambitions, diplomats close to the talks said.

They made "significant progress," but there is no "final result yet," Zarif told reporters early Thursday at the Swiss hotel hosting the negotiations, saying he felt "lucky" to have slept for two hours.

As German Foreign Minister Frank-Walter Steinmeier canceled a planned trip to the Baltics to stay in Lausanne, Iran's nuclear chief Ali Akbar Salehi spoke of "lots of progress" and said that the "sunset is close".

But as negotiators from the powers, without Iran, after a break held a two-and-a-half hour meeting to review progress on Thursday morning, signs emerged that they were not in fact on the verge of a breakthrough.

"The conclusion is far from being imminent," one Western diplomat said.

After 18 months of intense negotiations, the six world powers -- Britain, China, France, Germany, Russia and the United States -- and Iran are hoping to agree a deal that puts a lid on 12 years of dangerously rising tensions.

The aim is to turn the framework they want to leave Lausanne with into a comprehensive accord backed by specific technical commitments by June 30 when an interim deal struck in November 2013 expires.

The stakes were high, French Foreign Minister Laurent Fabius said, adding that they involved "Iran's reintegration into the international community."

Failure may set the United States and Israel on a road to military action to thwart Iran's nuclear drive.

Israeli Intelligence Minister Yuval Steinitz, whose country is widely assumed to have the bomb, said Thursday that the "military option is on the table".

Brigadier General Hossein Dehghan, the Iranian defense minister, said that similar comments Tuesday by Pentagon chief Ashton Carter were "designed to affect the rational atmosphere" of the nuclear talks.

The White House said overnight that the talks were still "productive" and progress was being made.

"But if we are in a situation where we sense that the talks have stalled then yes, the United States and the international community is prepared to walk away," said White House spokesman Josh Earnest.

Iran's chief negotiator Abbas Araghchi had said there were two main sticking points -- a mechanism for lifting crippling sanctions against the Islamic republic, and the country's research and development of new nuclear machinery.

Global powers want Iran to scale down its nuclear program to extend the "breakout" time needed to assemble enough nuclear material to make a bomb, which Iran has always denied seeking.

But Iranian negotiators are under pressure from domestic hardliners not to give too much away -- while also delivering on President Hassan Rouhani's promise to win the lifting of sanctions.

Global powers have refused an immediate end to all sanctions, preferring instead a phased suspension to enable them to be put back in place if Iran violates the deal.

The issue of suspending U.N. sanctions is particularly tricky -- Iran is also subject to U.S. and EU measures -- with discord among the powers about the mechanism for a "snap-back" mechanism if needed.

U.S. President Barack Obama also needs a deal which he can sell to hostile Republicans in Congress, who remain skeptical of Iran's pledges and are threatening to push for new sanctions from April 14.

Republicans and U.S. allies like Israel and Saudi Arabia fear that if too much of Iran's nuclear program is left intact, it will still have the ability to obtain a nuclear bomb.

Later on Thursday, Iran's defense minister has lambasted his U.S. counterpart's comments about military options against Tehran still being on the table despite ongoing nuclear talks, saying they showed America cannot be trusted.

Brigadier General Hossein Dehghan, quoted by the official IRNA news agency Thursday, said Pentagon chief Ashton Carter's remarks were "designed to affect the rational atmosphere of negotiations" between Iran and world powers.

Carter, who became defense secretary in February, said in an interview Tuesday with NBC News that if a nuclear deal is not reached "the military option certainly will remain on the table."

"If there is a good agreement to have, obviously it is worth waiting for and completing the negotiations," he added.

Dehghan dismissed Carter's words as an "empty" threat that would not affect Iran's "reasonable, rational and fair position" in the talks, though they had come at a "sensitive and difficult" time.

"The said remarks are a testament to the Islamic republic's distrust for the U.S.," he said, accusing Carter of "suffering from Alzheimer's disease".

"If Ashton Carter remembered America's previous and recent defeats in the region and the world, he would refrain from making such empty remarks," Dehghan said.

Iran is "at all times and in all situations ready to retaliate against any hostile threats from aggressors," he added.