Tehran of its intention to resume uranium enrichment at its Fordow facility, the United States on Monday said it would withdraw its sanction waiver to Iran’s facility.

US Secretary of State Mike Pompeo on Monday announced the US decision to end its sanction waiver for Iran’s Fordow nuclear facility, terming the Tehran assertion as “one of nuclear extortion” and warning that it would only deepen Iran’s political and economic isolation from the world.

“The right amount of uranium enrichment for the world’s largest state sponsor of terror is zero,” Pompeo told reporters at the Foggy Bottom headquarters of the State Department.

Iran originally built Fordow as a fortified, underground bunker to conduct secret uranium enrichment work, and there is no legitimate reason for Iran to resume enrichment at this previously clandestine site, he said.