The acting director-general of the United Nations nuclear watchdog is in Tehran for meetings after Iran announced it would begin using advanced centrifuges prohibited by its 2015 atomic deal with world powers.

Iranian state television aired Sunday video of Cornel Feruta in the capital, Tehran.

Feruta is to meet Mohammad Javad Zarif, Iran’s Foreign Minister, and Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran.

Iran on Saturday announced it would begin using two types of advanced centrifuges that could enrich uranium “much more beyond” current levels to weapons-grade material.

While insisting Iran doesn’t seek a nuclear weapon, the comments by Behrouz Kamalvandi of the Atomic Energy Organization of Iran threatened that his country could push uranium enrichment to new levels.

Iran already has crept past limits the deal imposed on nuclear enrichment and its uranium stockpile. It is trying to pressure Europe to offer a way to sell crude oil abroad despite U.S. sanctions.

The U.S. pulled out of the nuclear deal over a year ago, raising tensions.