The International Atomic Energy Agency (IAEA) says Iran is repeatedly violating the 130-ton limit of heavy water it uses to moderate nuclear fission in its reactors and has not made the excess available on the open market, as the Iran nuclear deal calls for.

Reuters:

Officials from the six other countries that signed the deal, including the United States, have expressed frustration over the breach and said the limit should be seen as firm.

Iran's overstepping of the 130-tonne threshold also raises questions about how U.S. President-elect Donald Trump - who has strongly criticized the deal and said he will "police that contract so tough they (the Iranians) don't have a chance" - would handle any similar case once he takes office.

"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 the text of a speech to his agency's Board of Governors, using the acronym for the deal's full name, the Joint Comprehensive Plan of Action.

Last week's report said Amano had expressed "concerns" to Iran over its stock of heavy water, a material used as a moderator in reactors like Iran's unfinished one at Arak, which had its core removed and made unusable under the deal.

The agreement places restrictions on Iran's atomic activities - monitored by the IAEA - in exchange for the lifting of international sanctions against the Islamic Republic.

Rather than setting a strict limit on heavy water as it does for enriched uranium, the deal estimates Iran's needs to be 130 tonnes and says any amount beyond its needs "will be made available for export to the international market".

The limit on heavy water is designed to make it difficult for Iran to use its nuclear reactors to manufacture plutonium – a material used in nuclear weapons.  With limits placed on Iran's ability to enrich uranium, it is critical to keeping Iran from making a plutonium bomb that there be strict controls on how much heavy water the Iranians can manufacture.  That Iran is repeatedly violating these limits is worrying.

With Donald Trump's election victory, Iran can see the writing on the wall.  Trump has promised to strictly enforce the deal or scrap it.  Under President Obama, Iran has been used to getting its way with interpreting some of the finer points of the nuclear deal in Iran's favor.  The Iranians have also been successful in forcing the U.S. and Western powers to keep secret several "side deals" that also favor Iran.

What can Trump do?  There is a laborious process by which the U.S. could take Iran to task for its cheating by convening a panel to examine whether Iran is in compliance or not.  This would take months, and in the end, no one expects Russia, China, or the European powers to cause the sanctions to "snap back," as President Obama so ridiculously claimed in selling the deal.

So Trump has a decision to make, and he will probably have to make it very early in his term: scuttle the deal unilaterally or go through the motions of convening a compliance panel.  Iran may be setting up the U.S. to take the blame for the collapse of the deal – an agreement most of the United States government opposed from the start.  But Iran has been taking advantage of President Obama's desperate desire to maintain his biggest foreign policy triumph at any cost – a reality that will probably be lost or deliberately ignored by the U.N. who no doubt would heavily criticize Trump for abrogating a deal that Iran has repeatedly violated.