Iran nuclear deal deadline extended to July 1

John Kerry and Hassan Rouhani said that real progress has been made in the talks and raised hopes a deal could eventually be sealed

Iran and world powers missed a deadline to clinch a landmark nuclear deal and defuse a 12-year standoff but gave themselves seven more months to reach agreement.

The failure followed an intensive five-day diplomatic push in the Austrian capital Vienna involving the foreign ministers of Iran, the United States, Russia, China, Britain, France and Germany.

But US Secretary of State John Kerry, speaking in Vienna, and Iranian President Hassan Rouhani, speaking in Tehran, yesterday said real progress had been made in the talks and raised hopes a deal could eventually be sealed.

"This path of negotiation will reach a final agreement," Rouhani said on state television. "Most of the gaps have been removed."

In their second extension this year, Iran and the five permanent members of the UN Security Council plus Germany, known as the P5+1, will seek to strike an outline deal by March and to nail down a full technical accord by July 1, officials said.

"These talks aren't going to suddenly get easier just because we extend them," Kerry said as he and other officials conceded a midnight yesterday deadline would be missed.

"They are tough. They have been tough and they are going to stay tough," he told hundreds of journalists crowded into a tent outside the 19th century palace where the talks were held.

"But in these last days in Vienna we have made real and substantial progress and we have seen new ideas surface. And that is why we are jointly, the P5+1 six nations and Iran, extending these talks for seven months."

In the best chance to resolve the standoff over Iran's nuclear programme, the P5+1 world powers have been for months seeking to turn an interim deal into a lasting accord.

Such an agreement is aimed at easing fears that Tehran will develop nuclear weapons under the guise of its civilian activities, an ambition Iran denies.

It could see painful sanctions on Iran lifted, silence talk of war and usher in a new era of cooperation between Washington and Tehran, which have called each other the 'axis of evil' and the 'Great Satan.'

A deal could begin a process in which the 'relationship between Iran and the world, and the region, begins to change,' US President Barack Obama said in an ABC News television interview Sunday.

But a last-ditch diplomatic blitz in Vienna in recent days involving Kerry and the other foreign ministers failed to bridge the remaining gaps.