TEHRAN, Iran — Iran said Monday that it would breach internationally agreed-upon curbs on its stock of low-enriched uranium in 10 days, a move likely to strain already high tensions with Washington, but it added that European nations still had time to save a landmark nuclear deal.

"We have quadrupled the rate of enrichment and even increased it more recently, so that in 10 days it will bypass the 300 kg (661 pounds) limit," Behrouz Kamalvandi, a spokesman for Iran's Atomic Energy Organization, said on state TV.

The announcement indicated that Iran's determination to break from the landmark 2015 accord, which has steadily unraveled since the Trump administration pulled the United States out of the deal last year and re-imposed tough economic sanctions on Iran, sending its economy into free-fall.

Kamalvandi made the announcement at a news conference with local journalists at Iran's Arak heavy water facility, which was carried live on state television.

Tehran said in May that it would reduce compliance with the nuclear pact, which it agreed to with world powers in 2015, in protest at the United States' decision to unilaterally pull out of the agreement and re-impose sanctions last year.

The deal aimed to extend the time it would theoretically take Iran to produce enough fissile material for an atomic bomb from several months to a minimum of one year.

However, Kamalvandi added that European countries still had time to save a nuclear deal.

Iran has repeatedly criticized delays in setting up a European mechanism that would shield trade with Iran from U.S. sanctions in an effort to save the nuclear deal.

"There is still time for the Europeans. ... But the Europeans have expressed indirectly their inability to act. They should not think that after 60 days (the deadline Iran set in May), they will have another 60-day opportunity," Kamalvandi said.

Ahead of a meeting of European Union foreign ministers, German Foreign Minister Heiko Mass said in a tweet that "it's high time for 'diplomacy first,'" adding that the E.U. could "contribute to deescalating the situation in the Middle East."

The comments come in the wake of suspected attacks on oil tankers last week in the region, attacks that Washington has blamed on Iran. Tensions have recently spiked between Iran and the United States, a year after President Donald Trump unilaterally withdrew America from the nuclear deal.

Speaking on Fox News Sunday, Secretary of State Mike Pompeo claimed that intelligence officials have "lots of data, lots of evidence," tying Iran to the attacks, although he did not provide any specifics.