OTTAWA -- The country's top military commander came out strongly in favour of acquiring armed drones for future operations in a bold statement Monday that is likely to make the Liberal government uncomfortable.

Gen. Jonathan Vance, in an appearance before the Senate defence and security committee, said he has raised the priority for the air force's drone program, which has been in the planning stages and proceeding in fits and starts for more than a decade.

Remotely piloted aircraft are important not only for surveillance at home, but to contribute to multi-national missions overseas, where the ability to strike at an enemy is necessary, the defence chief told reporters following his testimony.

"I think it's important for a military force to have a range of options available to it," he said. "In my view, there's no point in having a UAV that can see a danger but can't strike, if it needs to."

The Liberals made buying surveillance drones a commitment in their election platform last fall and put out a quiet call to defence contractors in January for their ideas on what systems could be provided.

But the air force, which has long advocated for an armed drone system, made the option of weaponizing the platform one of its key considerations. In fact, the request for information, which closes in mid-April, was specific and said the country was looking for a drone that could deliver one Hellfire missile and two 113-kilogram bombs.

A spokesman for National Defence recently acknowledged the air force wants a strike capability, but the drones Canada intends to buy will "be used primarily for surveillance and reconnaissance" of the coastlines and the Arctic.

Legal experts have warned that the government and the military not only need to develop a policy for using armed drones, but must also create a legal framework that clearly makes the government accountable for their use.

In the U.S., the CIA and Pentagon both run drone programs, which have faced public scrutiny and increasing criticism in light of the dramatic rise in strikes over the last eight years and claims of civilian casualties.

Vance said he's confidence the legal and technical issues can be thrashed out during the Liberal government's upcoming defence policy review.

"I suspect there will be debate, particularly as it applies to Canadian operations," he said. "So, I think it'll form a part of that."

The effort to buy drones -- a capability most other nations already possess -- has been long and tortuous.

The air force started research and shopping a decade ago, with a budget of roughly $500 million. Some estimates peg the revised program at $3.2 billion.

The plan was largely shelved when the Conservative government had to put a temporary system in place during the Afghan war. The country leased Heron drones from an Israeli defence company, but gave up the platforms when the Kandahar combat mission came to an end in 2011.

The program to provide a more all-encompassing capability only restarted a few years ago and the department's own acquisition guide doesn't anticipate a contract award until 2020, with final delivery of the system in 2025.