Foreign Affairs Minister John Baird is telling the United Nations secretary general to stay away from a summit of non-aligned nations in Iran this week.
Mr. Baird said Tehran will use Ban Ki-moon's presence at the meeting of more than 100 countries for its own propaganda.
"I just think they're going to exploit his presence there for nefarious purposes," Mr. Baird told reporters today.
"We're concerned that his presence there will be used to bolster the regime politically. Obviously we wrote in strong terms to encourage him, like a number of our allies did, to reflect on that before he goes."
The minister says Iran has pledged to destroy Israel and has an abysmal human rights record.
Mr. Baird sent Mr. Ban a letter last week outlining his concerns, which mirror those of Israel.
"Iran's current rulers will use your presence to further their own, hateful purposes. Such a visit would serve only to legitimize and condone the record of this regime, which Canada views as the single most significant risk to global peace and security today," says the Aug. 23 letter.
The West believes Iran is pursuing a nuclear weapons program, but Tehran denies this.
There has been growing speculation lately about a possible pre-emptive Israeli military strike against Iran's nuclear program.