Iran's ambassador to the IAEA Reza Najafi
Iran's ambassador to the IAEA Reza NajafiReuters

Iran has succeeded in violating the terms of its nuclear deal with the West, a confidential report by the UN nuclear watchdog seen by Reuters revealed on Wednesday. 

According to the International Atomic Energy Agency's (IAEA) report, Iran's stockpile of low-enriched uranium has actually increased in the past three months by 460.2 kilograms. 

Under the deal signed with six world powers in July, Iran's stockpile of low-enriched uranium must be slashed to no more than 300 kilograms. 

However, according to a senior diplomat the current increase is the result of a normal fluctuation and "there is nothing special in that."

IAEA is already under fire for allowing Iran to inspect its own covert nuclear sites, most significantly the Parchin military base where nuclear detonator tests have reportedly been conducted.

IAEA's report also noted that Iran had begun dismantling centrifuges at Fordow and Natanz, its two main uranium enrichment sites. 

The nuclear deal stipulates Iran reduce its number of installed centrifuges from 19,000 to around 6,100.

"They have been dismantling centrifuges that did not contain hexafluoride," the senior diplomat said, referring to uranium hexafluoride, a substance which can be used to enrich uranium for use in weapons. 

Some 4,500 centrifuges have so far been removed from Natanz and Fordow, despite reports a week ago that Iran had stopped dismantling centrifuges at the two sites following complaints from conservative lawmakers, thereby breaching the nuclear deal that calls for their dismantlement.

Iran also recently bought a plane to deploy troops in Syria in violation of sanctions still in place in the nuclear deal. It has threatened to end the nuclear deal if all non-nuclear sanctions are lifted against it - a condition not present in the deal.