The Liberal government will withdraw Canada's fighter jets from the fight against ISIS, but CBC News has learned that not all military aircraft will be pulled from the mission in Iraq and Syria.

The Department of National Defence said Thursday that while the CF-18s will be withdrawn from the U.S.-led coalition combat mission, other planes — two Auroras, which are surveillance aircraft, two transport planes and a Polaris in-flight refuelling plane — will still fly alongside our allies.

Prime Minister Justin Trudeau has faced criticism at home for withdrawing the jets, but Canada's international allies have not asked the government to reconsider its position, according to a senior adviser to Trudeau.

Trudeau sat down for a bilateral meeting with British Prime Minister David Cameron yesterday in London.

The adviser, who spoke to reporters on background and on condition that he not be named, said there was "absolutely no pressure for Canada to continue its contribution to the bombing mission."

Meanwhile, Cameron made a strong appeal to his own Parliament today to extend the mission of British fighter jets into Syria.

In making his case, Cameron told members of Parliament that "you can't subcontract out security."

Leaders have been 'satisfied'

At various meetings over the past couple of weeks, Trudeau has discussed the mission with world leaders. He has been asked to sometimes explain Canada's position, but the adviser said other leaders have been "satisfied" with the response from the prime minister.

Prime Minister Justin Trudeau met with British Prime Minister David Cameron at 10 Downing Street in London on Wednesday. The pair discussed a range of topics, including international security. (Justin Tallis/Associated Press)

Canada will not be part of the bombing mission, but will increase the number of military trainers on the ground.

There is a strong sense from other allies that training is a "useful contribution," said the adviser.

When Trudeau was asked yesterday in London by reporters if he would be giving his allies any sense of when more trainers would arrive or how many Canada would contribute, the prime minister would only say there's a continuing conversation with allies to see how and where Canada can be most useful.

Trudeau also made the point that of the 60 countries that make up the coalition, none of them are doing everything.

Speaking to reporters in Malta Thursday, Foreign Affairs Minister Stéphane Dion said his government was asking for a bit of patience while it figures out Canada's role going forward, and so far its message had been well-received.

"We want to be more effective in the coalition," he said, adding that the allies Canada is consulting with "are very open to giving us their suggestions about what Canada may do other than two per cent of the [airstrikes.]"

'We have to step it up'

After the deadly attacks in Paris, interim Conservative Leader Rona Ambrose called on the Liberal government to "immediately" reverse its decision to pull fighter jets from the U.S.-led bombing mission against the Islamic State of Iraq and Syria (ISIS), which claimed responsibility for the attacks.

"The fight against ISIS requires a strong humanitarian response, but also a military response," Ambrose said earlier this month. "It's important that we remain resolute and support our allies."

James Bezan, the Conservative defence critic, made the case again on CBC News Network's Power & Politics on Wednesday, saying that pulling Canadian fighter jets out of the fight against ISIS is a "weak response."

"ISIS is ramping up its activities. We need to be there, as Canada always has been historically, standing shoulder to shoulder and doing the heavy lifting as best as we possibly can," he said.

"If we're going to actually degrade and defeat ISIS, we have to have a more robust military intervention to stop the humanitarian crisis, to stop the genocide that's taking place by ISIS terrorists. We have to step it up, not step back."

British High Commissioner to Canada Howard Drake discusses David Cameron's push to extend the U.K.'s airstrike campaign to Syria 8:07

Before Trudeau's meeting with Cameron, Howard Drake, the British high commissioner to Canada, told Power & Politics on Monday that it's for Canada to decide how it will contribute to the battle against ISIS.

"We've made very clear that it is for each country, for each participant in the coalition, to indicate and make clear where it thinks it can make the best contribution, and that's what Prime Minister Trudeau has said he's going to do," Drake said.

"We happen to think, and other allies happen to think ... that bombing is a very essential part of this to protect our interests."