President Donald Trump issued an executive order on Wednesday prohibiting the purchase of Iranian iron, steel, aluminum and copper, ratcheting up tensions with the Islamic Republic less than a day after it declared it may begin enriching uranium again in 60 days.

Trump said in his order that the prohibition on trading in the Iranian metals is aimed at preventing Tehran from developing a nuclear weapon or intercontinental ballistic missiles.

The president said in the order he seeks to deny the Iranian government money “that may be used to provide funding and support for the proliferation of weapons of mass destruction, terrorist groups and networks, campaigns of regional aggression, and military expansion.”

Iran said earlier on Wednesday that it would abandon limits on uranium enrichment that it agreed to under the 2015 nuclear accord negotiated with Trump’s predecessor, Barack Obama, unless European signatories to the deal can find a way for the country to engage in trade despite U.S. sanctions.

Earlier this month, the U.S. revoked waivers that had allowed eight countries including India and China to import Iranian oil despite American sanctions. The Trump administration seeks to drive Iranian oil exports to zero to force Tehran to abandon support for militant groups in the Mideast and renegotiate the 2015 accord.

Trump has criticized the deal Obama negotiated as insufficiently strict on the Iranian regime.

“We call on the regime to abandon its nuclear ambitions, change its destructive behavior, respect the rights of its people, and return in good faith to the negotiating table,” Trump said in a statement.