Iran on Monday said that it has exceeded the 300 kg limit of low-enriched uranium stockpile that was fixed during a nuclear deal in 2015 along with other countries, Reuters quoted Foreign Minister Mohammad Javad Zaveri as saying. The announcement comes amid escalating tension between Iran and the United States.

“I have been informed that we have surpassed the 300-kilogram limit on our enriched uranium stockpile,” Iran’s official Islamic Republic News Agency quoted Zarif as saying. He also said that the “measures are reversible” but warned that if Europe does not take the required action to uphold their side of the deal then Iran can continue to not keep to the terms of the agreement.

Zarif, however, did not say exactly how much low-enriched uranium was in possession of the country. United Nations’ nuclear watchdog International Atomic Energy Agency said it was trying to verify the claims. “Our inspectors are on the ground and they will report to headquarters as soon as the [low-enriched uranium] stockpile has been verified,” AP quoted the agency’s officials as saying.

Breaching the stockpile limit does not radically change the fact that it would take one year for Iran to possess enough material for an atomic bomb in case it plans to make one, the news agency quoted experts as saying. Iran, has in the past, claimed that its nuclear programme was for peaceful purposes despite concerns.

However, Iran’s move will impact the terms of the nuclear deal under which it had agreed to have less than 300 kg of uranium enriched to a maximum of 3.67%. In June, the country had announced that it was planning to increase its uranium enrichment capacity.

Iran has often threatened to cross the 300-kg limit unless it got some relief from the sanctions imposed on the country. The other signatories of the nuclear deal, which was originally signed by six world powers and Iran, were struggling to keep it afloat after United States President Donald Trump walked out of it.