International Atomic Energy Agency Director General Rafael Grossi will meet on Saturday with Iranian President Ebrahim Raisi in Tehran in a bid to “restart the relationship at the highest level,” AFP reported Wednesday.

It comes after the IAEA confirmed in a report that its inspectors found uranium enriched to 83.7 percent at Iran’s underground nuclear site in Fordow.

The U.N. nuclear watchdog’s confidential quarterly report stated that “particles” of the substance, just below the 90% enrichment level considered “military grade,” had been detected.

The new report confirms that on Jan. 21, two cascades of IR-6 centrifuges at the Fordow Fuel Enrichment Plant had been configured in a manner “substantially different” from what had been previously declared. Inspectors took samples at the site the following day, which showed particles of uranium enriched up to 83.7%, the report said.

The IAEA has since requested “clarification” and said that “discussions [with Iran] are still ongoing” to determine how the threshold was reached.

On Tuesday, U.S. Under Secretary of Defense for Policy Colin Kahl warned that Tehran could produce enough fissile material for a nuclear bomb in under two weeks, comments that echoed those made in an interview aired over the weekend by CIA chief William Burns.

Israeli Prime Minister Benjamin Netanyahu said last week that history has shown that in the absence of a credible military threat or actual military action, Iran will become a nuclear power.

“The longer you wait, the harder that becomes [to prevent]. We’ve waited very long. I can tell you that I will do everything in my power to prevent Iran from acquiring nuclear weapons. That is not merely an Israeli interest; it’s an American interest; it’s in the interest of the entire world,” he said.