“The text that was sent (by Iran) has a constructive approach aimed at finalising the negotiations,” Kanaani, was quoted as saying by state broadcaster IRIB.

A US official, who spoke on condition of anonymity, said the US government had received the Iranian response, but gave no characterisation of the document. The US state department did not immediately respond to a request for comment.

The IRIB report said Iran’s response was sent to EU foreign policy chief Josep Borrell, who has been coordinating the negotiations. It gave no further details.

After 16 months of indirect talks between Tehran and Washington, Borrell said on Aug 8 the EU had laid down a final offer to overcome an impasse for the revival of the agreement.

Iran needs stronger guarantees from Washington for the revival of a 2015 nuclear deal, its foreign minister said on Wednesday, adding that the UN atomic watchdog should drop its “politically motivated probes” of Tehran’s nuclear work.

Under the 2015 pact, Iran had curbed its nuclear program in return for relief from US, EU and UN sanctions.

Then US president Donald Trump reneged on the deal in 2018, arguing that it was too generous to Tehran. He reimposed US sanctions on Iran, leading Tehran to resume previously banned nuclear activities and reviving US, European and Israeli fears that Iran may seek an atomic bomb.

Iran denies any such ambition.