90% of 'issues' solved

Uncertainty reigned at crunch US-Iran nuclear talks yesterday as US officials warned that key differences remained but Tehran said that almost all technical issues were resolved ahead of a March 31 deadline for the outlines of a deal.

"We have agreed on 90% of the technical issues," Iran's nuclear chief Ali Akbar Salehi was quoted by state television as saying from the marathon negotiations inside a plush hotel in the Swiss lakeside city of Lausanne.

"In most of the issues we have come to mutual agreements -- we have differences only in one major issue which we will try to solve in this evening's meeting" between Iran's Foreign Minister Mohammad Javad Zarif and US Secretary of State John Kerry, Salehi said.

The deal being sought by Kerry, Zarif and other negotiators including Salehi and US Energy Secretary Ernest Moniz will, they hope, convince the world that Iran will not develop nuclear weapons under the guise of its civilian programme.

The accord, due to be finalised by July, would involve Iran, which denies wanting the bomb, agreeing to scale down its nuclear activities to within strict limits in return for relief from sanctions suffocating its economy.

If they manage it and the accord holds, both sides hope it will end a 12-year standoff and potentially help normalise Iran's international relations at a particularly volatile time in the Middle East.

However, the White House sought to temper optimism about a seemingly imminent nuclear deal with Iran, warning that some difficult issues are yet to be resolved.

"In the mind of the president the odds have not moved," said White House spokesman Josh Earnest, warning that "at best" it is a 50/50 proposition.

Critics in the United States and in Iran's arch foe Israel, widely assumed to have nuclear weapons itself, fear that the mooted restrictions on Iran's nuclear programme won't go far enough.

In Washington 47 Republican senators last week wrote an open letter to Iran's leaders telling them that Congress could alter any deal and that a future president could tear it up.

US President Barack Obama, a Democrat, is also fighting to stop the Republicans bringing new legislation that would force him to submit any deal to Congress for approval.