The decision is part of an often furious debate among Iranian lawmakers over joining international conventions on money-laundering and terrorist financing.

It is currently alone with North Korea on the black-list of the Financial Action Task Force (FATF), adding to its woes in accessing global banking. Its status is due for review by the FATF later this month.

But conservative lawmakers strongly oppose new laws aimed at bringing Iran up to international standards, in the works since last year, and unveiled huge petitions against joining the Terrorism Financing Convention on the floor of parliament on Sunday.

They said it would cut off Iranian support to key regional allies, Lebanese Hezbollah and Palestinian Hamas, whose military wings are designated as terrorist organisations by the United States and European Union, among others.

They also said the legislation would condemn members of the Iran's Revolutionary Guards listed as terrorists by the US, including the head of its external operations, Qassem Soleimani.

"Why do we want to bind ourselves to frameworks and requirements which have been designed by our enemies?" said Hosseini Naghavi-Hosseini, spokesman for parliament's National Security and Foreign Policy commission.

Abbas Araghchi, deputy foreign minister, defended the efforts to join the FATF.

"This very parliament was the victim of Daesh (the Islamic State group) terrorism this time last year... Without international cooperation and joining international conventions, it is impossible to confront it," said Aragchi.

"Inside the country there are some holes and weaknesses in banking networks, which unfortunately facilitates terrorist groups and drug-smuggling," he added.

The Islamic State group (IS) carried out twin attacks last June on Iran's parliament and the tomb of revolutionary founder Ruhollah Khomeini, killing 17.

Iran, a majority Shiite country, is considered a primary enemy by Sunni jihadist groups such as Al-Qaeda and IS -- and has directly fought these groups in Syria and Iraq.

But with the US pulling out of the 2015 nuclear deal last month and ordering full sanctions to be reimposed on Iran, many say it is pointless to join the FATF.

The other parties to the nuclear deal -- Britain, France, Germany, China and Russia -- are working to salvage the deal and maintain trade ties, but most international banks already refuse to work with Iran for fear of US penalties.

"They didn't have financial and monetary ties with us during the JCPOA (nuclear deal). How can we expect to have such ties after joining this convention?" said Naghavi-Hosseini.

Lawmakers voted 138 to 103 (with six abstentions) on suspending the discussion around the Terrorism Financing Convention for two months, while they wait to see how the nuclear deal discussions play out, according to ISNA.