The spokesman for the Atomic Energy Organization of Iran (AEOI) says that Tehran has transferred an amount of its surplus heavy water to Oman for commercial purposes, according to Iran’s PressTV.

“In view of the progress of talks with several foreign firms and countries to purchase heavy water, some quantities of Iran's surplus production has been transferred to Oman," AEOI spokesman Behrouz Kamalvandi was quoted as saying on Sunday.

He reportedly added that further amounts of surplus heavy water will be sent to Oman in the future.

Earlier in the month, the International Atomic Energy Agency claimed in its quarterly report that Iran’s stocks of heavy water had slightly exceeded the 130-ton level set out in last year’s nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA).

Reuters reported on November 9 that the U.S. State Department has said that Iran is taking steps to ship out heavy water produced in excess of a soft limit set under its nuclear deal with major powers.

“It's important to note that Iran made no effort to hide this,” State Department spokesman Mark Toner told a regular press briefing when asked about the report, according to Reuters.

It is the second time Tehran has surpassed the 130 metric ton threshold for heavy water, a material used as a moderator in reactors like Iran's unfinished one at Arak, since the deal was put in place in January.  It had 130.1 tons of the material on November 8, the International Atomic Energy Agency said in a confidential report seen by Reuters.

Iran and the five permanent members of the United Nations Security Council – the United States, France, Britain, Russia and China – plus Germany signed the JCPOA in July 2015 and started implementing it in January 2016.  Under the JCPOA, Iran undertook to put limitations on its nuclear program in exchange for the removal of nuclear-related sanctions imposed against Tehran.

Iran’s PressTV reports Kamalvandi stressed on November 18 that Iran has remained committed to its JCPOA obligations, including those concerning its heavy water stockpiles.