Iran has announced plans for legislation to let it freeze terrorist-linked assets in line with its United Nations responsibilities.
If - as expected - the bill is ratified by parliament and by the hard-line Guardian Council, it will make Iran a member of the International Convention for the Suppression of the Financing of Terrorism, which was created in 1999 and came into force in 2002.
That commits Iran to banning the collecting of money intended to support terrorist actings, and to answering calls by other signatories for help with tracking terror funds.
But while Al-Qaeda will be included on its list of banned organisations, a government spokesman said, Hamas - the Palestinian extremist group banned by the European Union over the weekend - will not.
Despite US accusations to the contrary Hamas is not a terrorist group in Iran's view, the Iranian spokesman said.
"Defence against aggressors and occupiers is the legitimate right over any nation, and you cannot label these movements as terrorist movements," said the spokesman, Abdollah Ramazanzadeh.
A weekend meeting of European Union ministers decided to rescind a long-standing distinction made between Hamas's military wing, responsible for suicide bombings costing hundreds of lives, and its political wing, which provides vital health, education and food to thousands of Palestinians.
Exactly how the ban on the group will be implemented is yet to be determined, since charities across Europe contribute to the welfare activities and the EU does not want the flow of aid to be unduly disrupted.
Al-Qaeda's presence on Iran's list of groups whose assets are liable to seizure comes as little surprise.
Tehran has repeatedly said it holds al-Qaeda prisoners.
But its long-standing war of words with the US - whose President, George W Bush, labelled it part of an Axis of Evil in early 2002 - means it has resisted calls to hand them over.
It has also refused to identify which supposed al-Qaeda members it is holding, or to entertain suggestions that it might swap the prisoners for having the "Axis of Evil" tag withdrawn.