"This attack has led to increased tensions in the region," the advisory said. "There is an increased threat of attacks against Western interests and of terrorist attacks in general. Consider leaving by commercial means if it is safe to do so."
Iranian Major-General Qassem Soleimani, the head of the Iranian Revolutionary Guard Corps' Quds Force, along with Iraqi paramilitary leaders were killed in a targeted drone strike near Baghdad International Airport early Friday.
The United States has urged its citizens in Iraq to leave "immediately," following the airstrike.
Iran has vowed "harsh retaliation" against the United States for what Iranian President Hassan Rouhani has called a "heinous crime" after Soleimani was killed.
The airstrike has sparked calls among world leaders for de-escalation on both sides over fears of a greater conflict.
Canada also called on all sides to exercise restraint and pursue de-escalation after the U.S. airstrike. Canada is currently commanding a NATO mission in Iraq, which is a "non-combat, advisory and training" mission.