Iran’s President Hassan Rouhani has warned that Tehran will continue to scale back its commitments to the 2015 nuclear accord until the European Union fulfills promises that it made under the terms of the deal.

Rouhani, speaking on state television, said Iran would start working on more advanced uranium enrichment centrifuges, reports Asharq Al-Awsat, a pan-Arab daily newspaper. Such work would advance the Iranians toward the capability to construct a nuclear bomb.

He spoke of IR-9 centrifuges, reports the Associated Press. “It’s unclear what those centrifuges can do, though Iran has a host of advanced centrifuges that enrich uranium more rapidly than those allowed under the accord,” said the news agency.

He also called on European parties to the pact to salvage the deal by shielding Iran’s economy from U.S. penalties.

Iran has gradually withdrawn from its commitments to the pact in the aftermath of the U.S. pullout in May 2018, under President Donald Trump, and the imposition of American sanctions on the Islamic Republic.

The nuclear accord was reached in July 2015 between Iran and six world powers, including the U.S. Obama administration, as well as Russia, China, Britain, France, and Germany.