Iran has quadrupled its production of low-enriched uranium amid tensions with the U.S. over Tehran’s unravelling nuclear accord, two semi-official news agencies reported Monday.

The reports said the production is of uranium enriched only to the 3.67 per cent limit set by the 2015 nuclear deal that Tehran reached with world powers, but it means Iran soon will go beyond the stockpile limitations established by the accord.

Both the semi-official Fars and Tasnim news agencies reported on the quadrupled production quoting Behrouz Kamalvandi, spokesperson for Iran’s nuclear agency. He said the increase in production of 3.67 per cent enriched uranium does not mean Iran increased the number of centrifuges it has in use, another requirement of the deal.

He said Iran “in weeks” would reach the 300-kilogram limit set by the nuclear deal.

Kamalvandi said Iran had informed the International Atomic Energy Agency about its move. The IAEA did not immediately respond to a request for comment Monday.

This follows a warning from U.S. President Donald Trump that Iran it would face its “official end” if it threatened the U.S. again, and comes after days of heightened tensions sparked by the Trump administration’s deployment of bombers and an aircraft carrier to the Persian Gulf over still unspecified threats from Iran.

While Trump’s duelling approach of flattery and threats has become a hallmark of his foreign policy, the risks have only grown in dealing with Iran, where mistrust between Tehran and Washington stretch back four decades.