Iran's nuclear chief said Tuesday demands by the UN nuclear watchdog IAEA for access to a workshop making centrifuges are beyond NPT and unacceptable to Tehran.

He was referring to an installation in Karaj, west of Tehran that was the target of a sabotage attack in June, IAEA monitoring cameras were damaged in the incident and Iran has been refusing access fro the UN watchdog to replace the equipment.

"Karaj ... is outside of safeguards ... We act within the framework of safeguards and NPT (nuclear Non-Proliferation Treaty) and do not accept anything else," the head of Iran's Atomic Energy Organization, Mohammad Eslami, said.

Eslami said that monitoring in the Karaj facility is related to the 2015 nuclear agreement, JCPOA, and when the United States has withdrawn from the agreement and imposed sanctions, Iran has no reason to cooperate.

The IAEA has said that without access to the Karaj facility, it cannot guarantee of being fully informed about Iran’s nuclear activities.

Nuclear talks underway since April in Vienna to restore the JCPOA have so far failed to make breakthrough. The United States and its European allies have become pessimistic over Iran’s negotiating posture.