LONDON, United Kingdom – Iran's Foreign Minister Abbas Araghchi has vehemently rejected reports and satellite imagery indicating tunnels being secretly constructed near the Natanz nuclear site.

"The attempts by the Israeli regime and certain Special Interest groups to derail diplomacy—using a variety of tactics—are abundantly clear for all to see," Araghchi wrote in an X post on Wednesday.

The minister was responding to a report by the Institute for Science and International Security—a Washington-based think tank—which relied on satellite imagery, showing heavily protected tunnel systems and expanded security at the facility.

Araghchi downplayed the report as "fantastical claims," scaremongering, and an attempt at manipulation of public opinion.

Reacting to the satellite imagery, Rafael Grossi, the head of the International Atomic Energy Organization (IAEA), called on Iranian authorities to come clean and explain the newly built tunnels.

Tehran has not yet officially addressed Grossi's request, but Araghchi argued that "every single milligram of enriched uranium in Iran is under full and constant IAEA supervision and monitoring."

The IAEA, by contrast, has in a chain of past reports, complained about reduced oversight of Iran's nuclear program, and being particularly kept in the dark about "suspicious" activity at certain facilities.

The foreign minister wrote the X post while on a visit to Beijing with an agenda to "brief" Chinese officials in the lead-up to a third round of nuclear talks between Tehran and Washington expected in Muscat on Saturday.

Continuing clash over enrichment

Upon return from China, the chief diplomat expressed cautious hopes for progress in the upcoming round. Yet he once again criticized US authorities for their "contradictory" media statements on the content of the negotiations.

A contentious point in the talks continues to revolve around Iran's right to enrich uranium. Tehran insists that any deal must allow it to continue the activity, while it is prepared to scale the level down to a basic 3.67 percent.

However, in a podcast interview released on Wednesday, US Secretary of State Marco Rubio declared that if the Islamic Republic seeks to possess enriched uranium for peaceful purposes, it can import the material from abroad—signaling Washington's firm stance against allowing Tehran to retain an enrichment regime on its own.