"Diplomatic relations between Canada and Iran have been suspended," Baird said.

Baird cited Iran's nuclear program, its hostility toward Israel and Iranian military assistance to the government of President Bashar al-Assad of Syria, which is locked in civil war with rebels.

"Canada views the government of Iran as the most significant threat to global peace and security in the world today," Baird said in a statement, accusing Iran of showing blatant disregard for the safety of foreign diplomats.

"Under the circumstances, Canada can no longer maintain a diplomatic presence in Iran," he said, declaring that Iran had shown "blatant disregard" for the Vienna Convention's guarantee of protection for diplomats.

Ottawa has long had poor relations with Iran, in part because of its enmity toward close Canadian ally Israel.

The United States has not had a functioning embassy in Tehran since the 1979-81 hostage crisis, when 52 Americans were held for 444 days. Britain's embassy in Tehran has been closed since it was stormed by protesters last November.

During the hostage crisis, the Canadian embassy in Tehran sheltered six U.S. diplomats who had avoided capture, and then helped them leave Iran with Canadian passports in January 1980. The Canadian embassy then closed, reopening only in 1988.

*Reporting by David Ljunggren and Randall Palmer; Editing by Vicki Allen and Will Dunham