"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.
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.
"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.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
