The head of Iran's nuclear program insisted on Wednesday that his government would co-operate with international inspectors on any "new activities", The Associated Press reported.
His statement followed an AP report about Tehran's new underground system near a nuclear enrichment facility.
The report outlined how deep inside a mountain, the new tunnels near the Natanz facility are likely beyond the range of a last-ditch US weapon designed to destroy such sites.
Speaking to journalists Wednesday after a Cabinet meeting, Mohammad Eslami of the Atomic Energy Organization of Iran sought to describe the interest in the site as a case of Israel feeling pressured.
"The Islamic Republic of Iran is working under the IAEA safeguards, and whenever wants to start new activities, it will coordinate with the IAEA, and acts accordingly," Eslami said, using an acronym for the International Atomic Energy Agency, according to AP.
The IAEA did not respond to questions from AP about the construction at Natanz, located about 225 kilometers south of Tehran.
Iran and the IAEA have previously clashed over the agency’s probe into man-made uranium particles found at three undeclared sites in the country.
Adding fuel to the fire was an IAEA report in early March which found that inspectors in Iran had found uranium particles enriched 83.7%, nearly bomb grade, at the Fordow plant.
Rafael Grossi, head of the UN’s nuclear watchdog, then visited Tehran where he received assurances from Iran that surveillance cameras at several nuclear sites would be reconnected and the pace of inspections increased.
The discovery of the uranium at near bomb level came talks between Iran and world powers on reviving the 2015 Iran nuclear deal remain stalled and have been since September.