Three weeks before the second phase of US sanctions go into effect, the Iranian parliament agreed to join the convention against the funding of terrorism (CFT).
Parliament speaker Ali Larijani said 143 out of 268 lawmakers voted to join the CFT. The bill must be ratified by the Guardian Council, a constitutional authority, to become a law.
Tehran says it has been trying to implement international standards against money laundering and the funding of terrorism set by the Financial Action Task Force (FATF), but it has struggled to get the measures passed.
Foreign Minister Mohammad Javad Zarif had stated that Russia and China informed him that they will not carry out bank operations with Iran if it does not implement the international standards set by FATF.
Iran has long provided support to the Lebanese Hezbollah group as well as Palestinian armed groups, which Western countries view as terrorist organizations. Joining the CFT is unlikely to prevent Iran from continuing to support such groups.
Hardliners in Iran opposed the bill, saying it would erode the country's sovereignty, and hundreds of hardline students protested the bill outside parliament on Sunday.
Others saw the bill as a positive gesture toward European countries as they try to salvage the nuclear accord.
Foreign businesses say legislation that includes FATF guidelines is essential if they are to increase investment.
In May, the United States pulled out of a 2015 nuclear deal between world powers and Tehran and reimposed sanctions.
Washington has told countries they must halt imports of Iranian oil from November 4 or face US financial measures.
Prior to Sunday’s vote, Zarif said that neither him nor President Hassan Rouhani could guarantee that abiding by FATF could resolve Iran’s problems. He added, however, that he could guarantee that failure to respect it could provide important excuses for the American administration to increase Iran’s problems.
The Guardian Council has yet to declare its stance from the FATF. A spokesman said the issue may be on its agenda when it convenes next week, reported the ISNA news agency.