An Iranian flag flys outside the Vienna International Centre hosting the United Nations headquarters and the International Atomic Energy Agency in Vienna on July 3, 2014. (JOE KLAMAR / AFP)

TEHRAN - Iran has never had direct or indirect talks with the United States over the issues concerning the 2015 nuclear deal, Iran's Ministry of Foreign Affairs Spokesman Saeed Khatibzadeh said here on Monday.

"There is no dialogue between Iran and the United States because the Joint Comprehensive Plan of Action (JCPOA) has made it clear how the United States will return to the deal," Khatibzadeh told a weekly press conference.

Iran has insisted that, for any talks, the United States should return to the deal, from which the former US president withdrew in 2018, and lift anti-Iran sanctions

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Last month, the European Union offered to attend an informal meeting between Iran and other parties to the JCPOA, with the United States also attending as a guest.

Iran has insisted that, for any talks, the United States should return to the deal, from which the former US president withdrew in 2018, and lift anti-Iran sanctions.

In response to a query on a step-by-step plan of the US return to the JCPOA, Khatibzadeh said that Iran has never received it.

"We have close talks with the remaining parties of the nuclear deal, and we are waiting for the implementation of the JCPOA by the Europeans," he said.

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He added that Iran's mitigation of nuclear measures is reversible if the other parties fulfill their obligations.