The revelation is contained in a recently tabled House of Commons reply to a series of written questions posed by the New Democrats.
In the response, the Harper government says it hasn't pursued a so-called status-of-forces agreement with Iraq.
It says it has worked with the government of Haider al-Abadi in Baghdad to ensure appropriate protection for Canadian soldiers taking part in the campaign against the group known as the Islamic State of Iraq and the Levant.
The Commons response says a status-of-forces agreement is complex, takes time to arrange and is not usually pursued in time-sensitive situations — a point reinforced by Defence Minister Jason Kenney.
"The status forces agreements are, of course, binding , treaty-level international commitments that often take years to develop, and we don't have years to wait," Kenney told the Commons.
"Years to wait to save the Iraqi people from genocide; to save those women from sexual slavery; and to help work with two dozen other countries in reinforcing a critical aspect of international security."
But the fact the combat mission has been extended means Canada will be involved in Iraq for a while, and the friendly-fire death of Sgt. Andrew Doiron clearly demonstrates there's a need for a binding legal framework, said NDP defence critic Jack Harris.
"I don't know how you can have an extended mission without one," Harris said Wednesday. "How we can get by on a diplomatic note is something I cannot comprehend."
A status of forces agreement covers not only the conduct of foreign troops in a country and administrative matters such as customs, but can also contain mechanisms that ensure accountability with the host government.
Harris said that would be particularly useful in light of the friendly-fire incident and would've guaranteed a structured follow-up with the Iraqi and Kurdish authorities, rather an ad-hoc approach.
The government's written response describes an agreement as just one of several mechanisms the government can use.
"It seems as if short cuts are being taken here," said Harris, who described the government's legal justification for bombing Syria as similarly sketchy.
The year-long combat mission extension passed by Parliament expanded airstrikes by CF-18s into Syria after the Harper government had said — at the outset of the campaign — that it wouldn't go there.
Bombing a sovereign nation without its consent is frowned upon in the international community, but can be legally justified under United Nations provisions if it is considered an act of self-defence — or the nation in question has lost control of its territory, posing a global danger.
The Harper government used both arguments at various times, but some legal experts have questioned them, saying the self-defence argument requires proof of an imminent threat.
Obtaining a status of forces agreement in Iraq would be a tricky endeavour.
The United States withdrew all of its troops from the country in 2011 when it was unable to reach such an arrangement with the government in Baghdad.