The United States announced today that Iran had given "no indication" during the annual UN General Assembly of the date on which it will return to the negotiating table for the rescue of the 2015 agreement on Iran's nuclear program.
"The window is open, but it will not remain open forever," a senior US official warned on condition of anonymity.
Indirect talks between Washington and Tehran, which began in Vienna in April through Europeans, China and Russia - the other parties to the agreement - were suspended following the election in June of Iran's new president, the ultra-conservative Ebrahim.
"At the moment, there is no clear indication that Iran is ready to return and that it is trying to resolve the outstanding issues," he added.
"Nothing has happened, changed or made us more optimistic," he told the UN.