United States Secretary of State Antony Blinken warned Wednesday that time was running out for Iran to return to the nuclear deal after a report by the IAEA, the United Nation's nuclear watchdog.

"I'm not going to put a date on it. But we are getting closer to the point at which a strict return to compliance with the JCPOA does not reproduce the benefits that that agreement achieved," Blinken told reporters from Germany, where he is part of talks with US allies on the situation in Afghanistan.

In May, during an interview for ABC, Blinken said that the United States is yet to see serious steps from Iran to return to the nuclear agreement.

The International Atomic Energy Agency denounced the "lack of Iranian cooperation," which, according to the atomic watchdog, could "seriously undermine" the UN monitoring tasks in the country.

The agency said its monitoring at Iranian nuclear sites had been "seriously undermined" by Tehran’s suspension of some inspections since February.

The IAEA heavily criticized Iran for not answering its questions regarding the traces of uranium found in 3 unannounced sites, which could hinder resuming the talks on the revival of the nuclear agreement.

Commenting on the IAEA's report, the Permanent Representative of Iran to the UN, Kazem Gharibabadi, asserted Tuesday that "No one has the right to demand the cessation of Iran's nuclear activities."

In June, Iran's Permanent Representative to the International Energy Agency declared that the latest IAEA report at the time proves that Iran has been implementing the Strategic Measures Law, which was made to lift sanctions on Iran.

Iranian President Ebrahim Raisi stressed Sunday that the nuclear talks must coincide with the lifting of sanctions on Iran.

Raisi said Iran does not fear negotiations, "We consider them to be a diplomatic means," he said. However, western countries, especially the United States, are looking for pressuring Iran, he added, although the president noted that pressures have never worked against Iran.

Germany found the delay signaled by Tehran "far too long," Foreign Minister Heiko Maas said. Iran had said the nuclear talks to revive the 2015 nuclear agreement would not be resumed for two to three months.

The German minister said he had telephoned his new counterpart in Tehran to get him to "return more swiftly to the negotiating table."

Maas said Berlin still expects the new Iranian government to continue to support results from negotiations that had taken place so far.