Iran has dropped some of its main demands on resurrecting a deal to rein in Tehran's nuclear program, including its insistence that international inspectors close some probes of its atomic program, bringing the possibility of an agreement closer, a senior US official told Reuters on Monday.
The official, speaking on condition of anonymity because of the sensitivity of the matter, said that although Tehran has been saying Washington has made concessions, Iran has dropped some of its key demands.
"They came back last week and basically dropped the main hang-ups to a deal," the official said.
Earlier, Iran accused the United States of procrastinating in efforts to revive the nuclear deal, a charge denied by Washington.
US State Department spokesman Ned Price told reporters in Washington: "The notion that we have delayed this negotiation in any way is just not true."
For his part, the European Union's foreign policy chief said on Monday he hoped the United States would respond positively as early as this week to an EU proposal that aims to save a 2015 nuclear deal with Iran.
Josep Borrell said that Iran had given a "reasonable" response to the proposal, which follows 16 months of fitful, indirect US-Iranian talks with the EU shuttling between the parties.
"There was a proposal from me as coordinator of the negotiations saying 'this is the equilibrium we reached, I don't think we can improve it on one side or the other'... and there was a response from Iran that I considered reasonable," Borrell told a university event in the Spanish city of Santander.
"It was transmitted to the United States which has not yet responded formally... I hope the response will put an end to the negotiations," he added.