Armed drones are the way of the future for Canada's military, but conversations about how they are used need to be had before they are deployed on the battlefield, says Prime Minister Justin Trudeau.

Trudeau said at a news conference in Quebec Thursday that his government has discussed using remotely piloted vehicles of many different types.

"We know that's going to be part of the defence mix moving forward for most countries, if not all countries," Trudeau said when asked about armed drones being added to the Canadian Forces arsenal.

"However, whenever we take the decisions to use them in new or different ways there will be fulsome discussions about that."

At the same time, the country's military commander moved to dispel what he described as the "Hollywood movie" version of drones and how they would be employed by Canada.

Chief of Defence Staff Gen. Jonathan Vance said unmanned aerial vehicles (UAVs) would only be used by the military "against legitimate military targets under the laws of armed conflict."

He said drones as weapons are no different than using fighter bombers to attack targets, or even tanks and artillery.

"If [a target] needs to be struck to advance our tactical or strategic objectives, it will be struck," Vance said. "If we don't have a UAV, we're going to use artillery or a jet. UAVs are more precise."

Chief of the Defence Staff Gen. Jonathan Vance, shown in his office in Ottawa on Thursday, said that drones will be used as weapons, and are no different than using a fighter jet or a tank. (Justin Tang/Canadian Press)

A defence policy review announced by Defence Minister Harjit Sajjan Wednesday, which outlines Canada's defence policy for the next 20 years, states that armed drones are "proliferating among potential adversaries."

"Expanded proliferation," the review said, "combined with technological advancement, will mean that Canada is faced with a variety of possible threats from remotely piloted systems."

The review says that armed drones used against Canada could be makeshift devices piloted by "non-state actors" or they could be highly sophisticated and heavily armed aircraft deployed by national governments.

"In response, Canada will require the appropriate capabilities to identify and defend against these burgeoning threats," the review states.

The review goes on to state that a variety of remotely controlled vehicles will be integrated into the Forces' existing surveillance capabilities and will "enable the real-time flow of information that is so essential to operational success."

Aside from using drones to launch unmanned strikes against enemy targets, remotely controlled vehicles will also be used for bomb disposal, undersea surveillance, naval mine countermeasures and mapping.

Prime Minister Justin Trudeau explains the future uses of drones in the Canadian military. 1:19

The air force has been pushing for armed drones for years.

A December 2013 briefing note, prepared for the project management office at National Defence which oversees the drone program, said there would have to be government "support for a precision-strike capability," but the military anticipates "public concern."

The Pentagon and CIA have drone programs.

Both have been the subject of increasing scrutiny and criticism, particularly in light of the dramatic rise in strikes over the past decade and claims of civilian casualties, notably in the campaign against the Islamic State in Iraq and Syria.

The CIA's program of targeted assassination has been the most controversial, prompting Barack Obama's administration to pledge in 2013 to create "clear guidelines, oversight and accountability" when it comes to decisions to employ lethal force.

Civilian casualties

Vance suggested Canadian drones would not be used in that kind of way.

"I understand the debate," he said. "The debate is about something we're not going to use them for. This is not what we do."

But even in a military context there are concerns.

The Pentagon has estimated more than 350 civilians have died as a result of U.S. air strikes in the campaign against ISIS between August 2014 and March 2017.

But Airwars, a British-based, journalist-led monitoring group, put the estimate at 3,164 civilian deaths as a result of coalition air strikes.

The organization counts casualties in Iraq, Syria and Libya.

It is unclear how many of those deaths were related to drone strikes, but Airwars reported in 2015 that a full 50 per cent of Royal Air Force missions were carried out by unmanned vehicles.

Canada's Liberal government began quietly shopping for drones not long after being elected and asked defence contractors for expressions of interest.

Last year's defence acquisition guide suggested that the air force wouldn't see UAVs on the flight line until the early 2020s.

It's unclear whether the new defence policy will speed that up.