Describing parliament as "mature and wise", Khamenei said lawmakers "must independently make legislation on issues such as terrorism or combating money laundering".

"Of course some of the provisions of international conventions may be good but there's no need to join these conventions, citing these provisions," the supreme leader told a gathering of MPs, according to his official website.

Khamenei cautioned against signing up to global conventions when "we are not aware of the depth of their aims or (when) we know that they have problems."

Earlier this month Iran's parliament voted to suspend discussion of joining the UN Terrorism Financing Convention for two months, as Tehran waits to see whether its nuclear deal with world powers survives after the US pulled out of the landmark accord.

Debate among Iranian lawmakers on joining such global agreements is often furious, with conservatives warning signing up to the terrorism financing accord would cut off Iranian support to key regional allies Hezbollah and Hamas.

The military wings of both groups are designated as terrorist organisations by the United States and European Union, among others.

But the government has argued international cooperation is essential to confront terrorist groups which have targeted the country.

Iran's commitment to the UN convention is a condition for being removed from the blacklist of the Financial Action Task Force (FATF), a spot shared with North Korea.

Being on the blacklist of the inter-governmental body has added to Iran's woes in accessing global banking.

Iran's struggle to access international markets has been further compounded by the US decision to withdraw from the nuclear deal.

The remaining parties to the accord -- Britain, China, France, Germany and Russia -- have committed to staying in the deal.

But their companies risk falling foul of US sanctions if they continue to do business with Iran.