In an advisory posted on its website, the Department of Foreign Affairs also warned against non-essential travel to the African country.
"There is heightened risk of terrorism throughout Libya, including in Benghazi," it warned.
"Terrorist attacks could occur at any time and could target areas frequented by expatriates and foreign travellers."
In addition to Benghazi, it said, the security situation in the town of Bani Walid and the regions of Sabha and Kufra is also precarious.
Earlier, Britain, Germany and the Netherlands warned of an imminent threat against westerners in Libya, days after a deadly hostage crisis in neighbouring Algeria. European officials said schools were among the potential targets.
The warnings came a day after U.S. Secretary of State Hillary Clinton testified to Congress about the Sept. 11 attack on the U.S. diplomatic mission in Benghazi that killed four Americans, including the U.S. ambassador to Libya.
They also came as French troops battled al-Qaida-linked militants in the West African country of Mali, and followed the deaths of at least 37 foreign hostages seized by extremists in Algeria.
Canada is supporting the Mali mission with a military transport plane. Ottawa said Thursday the C-17 Globemaster would continue to ferry military equipment and vehicles between France and the Malian capital of Bamako until Feb. 15.
_ With files from The Associated Press.