The strikes were lifted at about the same time on the day Suleimani was killed last Friday in an American drone attack at Baghdad airport.
The UK has urged Iran not to carry out further "reckless and dangerous" attacks after Tehran fired missiles at military bases in Iraq hosting British and USA troops.
Iran has said it will institute reprisals.
"The news coming out of the Middle East is alarming for many of you, as such I thought it best to communicate with you directly to provide an update on Canada's missions in the region, and more importantly the status and well-being of your family and friends deployed in Iraq and Kuwait and elsewhere in the Region", the letter states.
More than a dozen ballistic missiles were fired at the military bases in Al Asad and Irbil.
President Donald Trump on Tuesday took to Twitter following the strike to say an "assessment of casualties and damages taking place now".
He said: "As we evaluate the situation and our response, we will take all necessary measures to protect and defend USA personnel, partners, and allies in the region". We have the most powerful & well-equipped military anywhere in the world, by far!
The Leader also paid tribute to General Soleimani for his assistance to regional nations in foiling the US' illegitimate plots against West Asia, saying the revered commander helped thwart the American plots in Iraq, Syria and Lebanon.
Iranian state television said 80 "American terrorists" had been killed and USA helicopters and military equipment damaged. It also asked Indian nationals in Iraq to be alert and to avoid traveling within the country. Meanwhile, the Directorate General for Civil Aviation (DGCA) said they have asked Indian airlines to remain vigilant and to take all precautions in airspaces above Iran, Iraq, the Gulf of Oman and the waters of the Persian Gulf.
But the details have been scarce, and Democrats have called for more information to be made public about the threat posed to United States forces by Soleimani.
Revenge by Iran and risk of escalation in tension between U.S. and Iran raises market concerns ...
President Trump has previously warned of more possible strikes if Iran retaliated.