The issue is part of broader talks underway in Vienna aiming to salvage the 2015 Iran nuclear deal that has been hanging by a thread since former president Donald Trump withdrew the US from it three years ago.

"No decision has been taken on the deletion of the data" recorded by the International Atomic Energy Agency (IAEA) cameras, said Iranian foreign ministry spokesman Saeed Khatibzadeh.

After Trump withdrew from the nuclear deal between Iran and major powers and ramped up punishing sanctions, the Islamic republic has taken steps away from its nuclear commitments.

Late last year, the conservative-dominated parliament passed a law that led Iran to restrict access to some of its nuclear facilities for IAEA inspectors from February.

Iran's moderate President Hassan Rouhani advised against the step, but the government followed through on the legislature's demand.

Tehran also denied the IAEA access to video recordings from monitoring equipment that the UN agency had installed at its sites to verify compliance.

The Atomic Energy Organisation of Iran said the cameras would keep running, but that the withheld footage would be deleted if US sanctions were not lifted within three months.

This period was later extended by a month but expired on June 24.

Since then, the IAEA has insisted on the "vital importance" that Iran extend the period again and urged Tehran to tell it whether it intends to do so.

But Tehran's response has been slow in coming.

"I insist that no negative or positive decision regarding the cameras and the previous agreement with the agency has been taken," Khatibzadeh said on Monday.

The decision is the responsibility of Iran's Supreme National Security Council, which is not known to have held a meeting on the subject since June 24.

The French foreign ministry called on Iran to resume cooperation with the IAEA and restore access "immediately and fully".

"We fully support the efforts of the IAEA to verify... Iran's respect for its nuclear commitments," it said.