Iran and world powers looked likely today to miss a midnight deadline to agree a long-awaited nuclear deal, with a Western diplomat saying they would agree an extension and meet again next month.
"Given progress made this weekend, talks headed to likely extension with experts and negotiating teams reconvening in December at a yet to be determined location," the diplomat said.
As the foreign ministers of Iran and the five permanent members of the UN Security Council plus Germany, the so-called P5+1, went into a meeting in Vienna, it was unclear how long the extension could be.
In the best chance in years to resolve the long-running standoff over Iran's nuclear programme, the P5+1 have been locked in talks with Iran for months, seeking to turn an interim deal that expires at midnight (2300 GMT) into a lasting accord.
Such an agreement, after a 12-year standoff, is aimed at easing fears that Tehran will develop nuclear weapons under the guise of its civilian activities, an ambition it strongly denies.
It could see painful sanctions on Iran lifted, silence talk of war and represent a much-needed success for both US President Barack Obama and his Iranian counterpart Hassan Rouhani.
A deal could begin a process in which the "relationship not just between Iran and us but the relationship between Iran and the world, and the region, begins to change," Obama said in an ABC News interview yesterday.
But a last-ditch diplomatic blitz in Vienna in recent days involving US Secretary of State John Kerry and other foreign ministers appeared to have failed to bridge the remaining major differences.
As a result, Iranian and US officials said late Sunday they had started talking about plan B -- the option of putting more time on the diplomatic clock.
"We have discussed an extentions but there is nothing detailed yet," an Iranian source told AFP.
This came after Kerry met his Iranian counterpart Mohammad Javad Zarif for the seventh time since Thursday but again apparently failed to break the deadlock.
Chinese Foreign Minister Wang Yi arrived in the Austrian capital early Monday, completing the line-up of all foreign ministers from the six powers.
They included Russian Foreign Minister Sergei Lavrov, a key player in the negotiations whose country has built a nuclear plant in Iran and is planning more.
