A senior Iranian parliamentarian says the Islamic Republic is in talks with a number of countries to sell its surplus heavy water, a nuclear byproduct, after the US decided to halt its purchases.

Kanal24 reports citing Press TV that Tehran has to sell its surplus heavy water under the 2015 nuclear agreement with world countries which requires that the inventory should not exceed 130 tonnes.

The Obama administration announced in late 2016 that it would spend more than $8 million to purchase Iranian heavy water but the incumbent US president Donald Trump put a stop to the purchases last month.

MP Mojtaba Zonnour, who heads the Iranian parliament's nuclear committee, said Washington's decision breached the spirit of the nuclear agreement known officially as the Joint Comprehensive Plan of Action (JCPOA).

"This American action is not a violation of the JCPOA but it is in conflict with its spirit," he said Monday, explaining that as per the text of the deal, the Americans are not required to buy heavy water from Iran.

"Theoretically, the Islamic Republic should engage in marketing to sell its heavy water and in this regard, negotiations have been held with some countries," Tasnim news agency quoted him as saying.

The lawmaker said if the US prevents other countries from buying the Iranian heavy water or imposes new sanctions in this regard, it will definitely constitute a violation of the JCPOA.

Europe and Russia are reportedly other clients of the Iranian heavy water but Zonnour said some of the countries interested in buying the material from Iran have faced pressures from the US and "backed down somewhat on their plans."

According to the lawmaker, Iran currently produces about 20 tonnes of heavy water a year, some of which is used domestically and the surplus is transported outside the country.

Zonnour put Iran's heavy water stock at the moment at 130 tonnes, the limit which should not be exceeded under the nuclear agreement.

"Part of this amount is kept inside the country and another part is transferred to an area under Iran's ownership in Oman so that the heavy water stock does not exceed 130 tonnes, and on the other hand, shipments are carried out more easily."

Last month, the head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi said the country had transferred 11 tonnes of heavy water to Oman in total.

Iran, he said, had sold 70 tonnes of heavy water, adding talks were underway with a number of countries, especially the Europeans, to sell more.