Last week, Iran exceeded its limit on heavy water for the second time since the agreement concerning its nuclear program was signed last January, the UN nuclear watchdog organization International Atomic Energy Agency (IAEA) reported.

The Joint Comprehensive Plan of Action (JCPOA), the agreement brokered by US President Barack Obama, limits Iran to 130 tons of heavy water. AFP reported that Iran exceeded the permitted level by 100 kilos and had undertaken to export five tons.

“It is important that such situations should be avoided in future in order to maintain international confidence in the implementation of the JCPOA,” IAEA chief Yukiya Amano said in a speech to the agency’s Board of Governors last week.

The concern is that heavy water, which is not radioactive, can be used as part of a nuclear weapons program. Some nuclear reactors that use unrefined plutonium as fuel also use heavy water. These reactors produce plutonium as a byproduct, which can be used in a nuclear weapons program. This bypasses the time-consuming process of uranium enrichment in centrifuges.

“Iran has … made preparations to transfer a quantity of heavy water out of the country,” Amano assured the Board of Governors. “Once it has been transferred, Iran’s stock of heavy water will be below 130 metric tonnes.”

No further details were given as to who would be receiving Iran’s excess heavy water or when that transfer will take place. The US has no domestic sources of heavy water and purchased 32 tons of heavy water from Iran in April, but US Department of Energy (DOE) officials said they would not be doing so in the future.

In response to the IAEA revelation of the Iranian violation, US State Department spokesman Mark Toner said that it was “important to note that Iran made no effort to hide this” and that he was “not sure whether that constitutes a formal violation”.

The deal with Iran came under fire during the recent US presidential campaign. President-elect Donald Trump called it “the stupidest deal of all time”. In a speech to the pro-Israel lobby group AIPAC in March, Trump declared that his “number one priority” would be to “dismantle the disastrous deal with Iran.”

All eyes will be on the president-elect to see if he holds true to this election promise, as he has already begun to backpedal on several pre-election vows. Walid Phares, a senior policy aide to Trump, addressed the president-elect’s developing platform in a BBC interview on Thursday.

“Ripping up is maybe a too strong of word, he’s gonna take that agreement, it’s been done before in international context, and then review it,” Phares said in the interview. “He will take the agreement, review it, send it to Congress, demand from the Iranians to restore a few issues or change a few issues, and there will be a discussion.”