Iranian Supreme Leader Ayatollah Ali Khamenei on Monday ordered his Atomic Energy Organization to prepare for weapons-grade uranium enrichment, bringing pressure against European powers desperate to keep the Iran nuclear deal alive after the U.S. withdrew last month.

“The Atomic Energy Organization of Iran is duty-bound to prepare the ground for achieving 190 thousand SWUs,” Khamenei said, insisting this production level would fall within the upper limit of what the nuclear deal (formally known as the JCPOA) allows.

Experts familiar with the terms of the deal disputed Khamenei’s assertion that 20 percent uranium enrichment is allowed. Uranium for civilian energy production is enriched to less than 4 percent.

A spokesman for Iran’s atomic energy agency said preparations would be made to increase the pace of uranium enrichment even further if the JCPOA collapses. He said a letter detailing Iran’s intentions has been sent to the International Atomic Energy Agency (IAEA).

“The Iranian nation will not tolerate to be under both sanctions and nuclear restrictions. The words uttered by some European states indicate that they expect the Iranian nation to both agree to comply with the nuclear deal undertakings and live under sanction,” Khamenei said on Monday, clarifying his threat.

The sanctions he referred to would be imposed by the United States following President Trump’s withdrawal from the JCPOA, so Khamenei was effectively cracking the whip on European leaders to talk Trump out of punishing Iran.

Khamenei previously ordered the Europeans to refrain from interfering with Iran’s ballistic missile program in any way, avoid interfering with Iran’s regional ambitions, ensure Iranian oil is sold for a profit in European markets, and provide banking services to Iranian companies. The Europeans have expressed unease with Iran’s ballistic missiles and its efforts to manipulate the politics of the Middle East.

Iranian Atomic Energy Organization director Ali Akbar Salehi said on Monday that Iran would not resume 20 percent enrichment immediately, but would lay the groundwork for doing so quickly if Europe does not comply with Khamenei’s demands.

“If we were progressing normally, it would have taken six or seven years, but this will now be ready in the coming weeks and months,” said Salehi.

The director said he might reveal more details of the new uranium centrifuge project during a visit to the Natanz enrichment facility on Wednesday.

Israeli Prime Minister Benjamin Netanyahu responded defiantly to the Ayatollah’s threats on Twitter:

Netanyahu is currently in Europe attempting to convince its leaders to follow the U.S. lead and withdraw from the JCPOA. On Monday he met with German Chancellor Angela Merkel, who defended the nuclear deal despite its flaws. Merkel did agree with Netanyahu that the IAEA should examine Iran’s nuclear program more closely.

Iranian officials maintain they have no interest in developing nuclear weapons, and in fact Khamenei claimed Islamic law prohibits the construction of nuclear bombs during his remarks.