Iranian Foreign Minister Mohammad Javad Zarif hit back at U.S. Secretary of State John Kerry late on Tuesday and blamed divisions between Western powers for the failure of talks over Tehran's disputed nuclear programme in Geneva last week.
Responding to remarks by Kerry in Abu Dhabi on Monday, Zarif said that blaming Iran only served to undermine confidence in the negotiations which are set for another round on Nov. 20.
The United States, the European Union and Iran worked intensively together for months on a proposal to help end the 10-year stand-off over Iran's nuclear programme, diplomats said, but talks in Geneva between Tehran and six world powers to agree the deal ended on Saturday without agreement.
French Foreign Minister Laurent Fabius said Paris could not accept a "fool's game" - in other words, a weak deal with Iran.
Diplomats from other Western nations at first reacted angrily and accused the French of trying to upstage the other powers and causing unnecessary trouble for the talks.
On Monday though, Kerry said the major powers were "unified on Saturday when we presented a proposal to the Iranians, and the French signed off on it, we signed off on it, and everybody agreed it was a fair proposal. There was unity, but Iran couldn't take it at that particular moment, they weren't able to accept that particular thing."
Zarif denied the Iranian side was to blame.
"Mr.Secretary, was it Iran that gutted over half of US draft Thursday night? and publicly commented against it Friday morning?" Zarif asked on Twitter.
"No amount of spinning can change what happened within 5+1 in Geneva from 6PM Thursday to 545 PM Saturday. But it can further erode confidence," he tweeted.
"We are committed to constructive engagement. Interaction on equal footing key to achieve shared objectives."
Western nations are determined to stop Iran from being able to make nuclear weapons and the United States and Israel have repeatedly said all options, a reference to possible military strikes, are on the table to achieve that aim.
Iran says its uranium enrichment programme is entirely peaceful and insists it has the right enrich uranium for civilian power plants and medical research.