Canada has come under fire from officials in Tehran for removing an exiled Iranian opposition group from its blacklist of "terror organisations".
Vic Toews, the Canadian minister of public safety, had announced the delisting of the People's Mujahedin of Iran ["Mujahedeen-e-Khalq" (MEK)], following similar moves made by the European Union and the United States.
Toews also announced the addition of the Quds Force, a unit of the Iranian Revolutionary Guard Corps, to the blacklist.
The Iranian foreign ministry responded on Monday, saying that Canada was "using the issue of terrorism as a tool and violating its international commitments".
The delisting "is a dangerous move that can weaken international peace and security", the statement added.
"The listing of 'terrorist' facilitates the prosecution of perpetrators and supporters of terrorism and plays a key role in countering terrorist financing"
- Vic Toews,
Canadian minister of public safety
The United Nations adopted a Canada-led condemnation of Iran last week, which accused Tehran for "widespread, systematic and egregious human rights violations".
"The listing of 'terrorist' facilitates the prosecution of perpetrators and supporters of terrorism and plays a key role in countering terrorist financing," said Toews in his announcement.
"The government of Canada remains vigilant against the threat of terrorism and is commited to ensuring that the list of terrorist entities remains current."
Canadian law allows officials to seize assets of any person or group named on the blacklist, but Tehran did not comment on the incluion of its Quds Force.
The MEK had a long history of violent attacks against both western and Iranian targets dating from the 1970s until 1992, when it stormed Iranian diplomatic missions in the US, Britain, Canada, Germany, Switzerland and France.
It gave up armed conflict in 1993 and has since been described as an "opposition movement in exile", saying it now works to overthrow the Iranian administration through peaceful means.
Canada cut diplomatic ties with Iran in September.