The acting director general of the International Atomic Energy Agency (IAEA) arrived in Tehran on Sunday for talks with Iranian officials on the country's nuclear program, state-run IRNA news agency reported.

A handout picture released by the Atomic Energy Organization of Iran on September 8, 2019, shows Acting Director General of the International Atomic Energy Agency (IAEA) Cornel Feruta (C) during a meeting with the head of Iran's Atomic Energy organization organization in Tehran. (Photo: VCG)

Cornel Feruta held talks with Ali Akbar Salehi, head of the Atomic Energy Organization of Iran, on the transparency of the Iranian nuclear program and the IAEA monitoring tasks at the country's nuclear sites.

"Unfortunately the European parties have failed to fulfill their commitments... The deal is not a one-way street and Iran will act accordingly as we have done so far by gradually downgrading our commitments," said Salehi.

"Iran will continue to reduce its nuclear commitments as long as the other parties fail to carry out their commitments," Salehi said, speaking after meeting Feruta.

Feruta is also scheduled to hold meeting with Iranian Foreign Minister Mohammad Javad Zarif on Sunday.

Feruta's visit to Tehran follows Iran's suspension of parts of its commitments to the 2015 nuclear deal, known as Joint Comprehensive Plan of Action (JCPOA). It also comes before a quarterly meeting of the IAEA's 35-country board of governors in Vienna on Monday.

"The actions they have taken are negative but not definitive. They can come back (to full compliance) and the path of dialogue is still open," French Foreign Minister Jean-Yves le Drian said on Sunday.

On Saturday, Iran officially announced a move to withdraw from part of its commitments to the JCPOA.

Following the announcement, Iran started up advanced centrifuges and activated 20 IR-4 centrifuges and 20 IR-6 centrifuges to boost the country's stockpile of enriched uranium.

Meanwhile, the country's foreign ministry spokesman on Sunday said an Iranian oil tanker at the center of a dispute between Tehran and western powers had reached its destination and sold its oil, state television reported. 

"The tanker has gone to its destination, the oil has been sold," spokesman Abbas Mousavi told the television station without disclosing whether the crude oil had been delivered. 

The tanker Adrian Darya 1, which went dark off Syria last week, has been photographed by satellite off the Syrian port of Tartus. 

"We will continue to put pressure on Iran and as President (Trump) said, there will be no waivers of any kind for Iran's oil," Reuters quoted Sigal Mandelker, U.S. Treasury Under Secretary for Terrorism and Financial Intelligence, as saying.