OTTAWA—Canada will pull six CF-18s from the combat mission against Islamic State militants in Iraq and Syria but two reconnaissance aircraft and an air-to-air refueller could remain to assist coalition aircraft in their own bombing sorties.

A senior defence department official said Thursday that discussions on the future of Canada’s contribution to the multinational campaign against ISIS continue and that no decisions have been made whether to leave other elements of the air task force in the region.

The Liberals have consistently pledged to end the “combat” mission and withdraw the CF-18s but have not ruled out allowing the missions by the other aircraft to continue.

Defence expert Dave Perry said the recon and refuelling aircraft play a valuable role appreciated by other nations. In particular, the two CP-140 Aurora surveillance aircraft, equipped with sophisticated radar and imaging sensors, gather valuable data for ground and air commanders.

“They provide an intelligence picture that supports the coalition writ large,” said Perry, a senior analyst with the Canadian Global Affairs Institute.

Meanwhile, the Conservatives are challenging the claim by Prime Minister Justin Trudeau that a lack of resources could be driving the decision to wind down the combat role.

Trudeau confirmed earlier this month that the CF-18s would be brought home. He said the Liberal government would instead deploy additional troops to beef up the ongoing training mission. Canada has 69 special operations forces soldiers in northern Iraq training local Kurdish militia to better fight Islamic forces.

But when pressed this week why Canada couldn’t continue the combat sorties and beef up the training mission at the same time, Trudeau responded that the country has “limited military investments.

“I mean for six planes we’re talking about 600 people to support those planes in various terms,” Trudeau told the Global News show The West Block.

“Decisions on sending Canada’s military into operational theatres will always be made on a case-by-case basis on what’s in our national interest, how best we can play a productive constructive role,” Trudeau told journalist Tom Clark.

But Conservative MP James Bezan said Trudeau was “misinformed” on his claim that the 600 personnel were required to support the six fighters alone. In fact, that group supports not only the CF-18s but also reconnaissance aircraft and air-to-air refueller as well.

Bezan also said there is no truth to Trudeau’s claim that an expanded mission would stretch the budget or capabilities of the armed forces.

“There is no reason we can’t do both and make it more robust. We have the troops. We increased the budget,” said Bezan, who served as former parliamentary secretary to the minister of defence in the previous Conservative government.

He said the Conservatives support a more robust training mission — and continuing the combat mission.

“We expect the Liberals will reverse their position on the CF-18s and we’ll support that, 100 per cent,” the Manitoba MP said in an interview.

“We still haven’t heard what is the real rationale for withdrawing the CF-18s and how does this help the fight against ISIS? How does this help our coalition partners? I think in all answers, it doesn’t,” he said.

As Canada begins winding up its combat operations, Britain is stepping up its military engagement. It unveiled a plan Thursday to begin airstrikes against targets in Syria in addition to the missions in Iraq it has already been flying.

In a strategy document laying out its renewed fight against the Islamic State, Britain said it was wrong to “sub-contract its security to other countries, and to expect the aircrews of other nations to carry the burdens and the risks of striking ISIL in Syria to stop.

Britain’s response is driven, in large measure, by concerns over ISIS’ ability to strike “far beyond” Iraq and Syria, as shown by the recent deadly attack in Paris. The terror threat to British citizens is “serious and undeniable,” the document said.