Iran will ship around 11 metric tons of heavy water out of the country in the next couple of days, according to people familiar with the plans, defusing a conflict with the U.S. and others over the Iranian nuclear deal.

Earlier this week, the head of the International Atomic Energy Agency, Yukiya Amano, expressed concerns that Iran had for the second time exceeded a 130 metric-ton threshold for its heavy-water stockpile. A metric ton is equivalent to 1.1 short tons.

He warned that a repetition of this breech could undermine confidence in the full implementation of the July 2015 agreement designed to stop Iran from acquiring nuclear weapons.

Weapons-grade plutonium can be separated from heavy water and used as material for a nuclear weapon, although there are a number of steps needed to do this. The nuclear accord therefore set a limit on Iran’s domestic stockpile of heavy water.

According to people familiar with the plans, Iran has already sent the 11 metric tons of heavy water to one of its ports, where it is under seal of the IAEA, the United Nations atomic agency that oversees implementation of the nuclear deal.

Read more at The Wall Street Journal.