Talks with the Pentagon about filling the Canadian air force's short-term need for jet fighters remain on track, said Defence Minister Harjit Sajjan.

Those negotiations for a so-called "interim capability" continue despite the Liberal government making a very public display at the Paris Air Show this week of snubbing Boeing executives.

The U.S. aerospace giant's commercial trade complaint against Montreal-based Bombardier has thrown the military contract into limbo.

Boeing wants trade regulators in Washington to investigate subsidies for Bombardier's CSeries aircraft, claiming they allow the Canadian company to export planes at well below cost.

The Liberals had intended to purchase 18 Super Hornet fighters — at a potential total program cost of between $5 billion and $7 billion — from Boeing. The deal was supposed to be a stopgap until the government can finalize the purchase of 88 permanent replacements for the aging CF-18 fleet.

After Boeing filed the trade complaint earlier this year, the government broke off contact with the U.S. company and said it was reviewing the "interim" fighter deal. It heightened the rhetoric last month, saying the aircraft maker was no longer the "trusted partner" it had been.

Sajjan said that, regardless of the trade dispute, the urgent requirement for fighters has not gone away and must be filled somehow.

"We're still continuing our discussions with the U.S. government, making sure that we fill this capability gap," Sajjan said.

Other options?

If Boeing has been frozen out, what is the Liberal government talking about with the Pentagon?

Sajjan said there are "other options," but refused to explain what they might be.

There are limited choices for a government-to-government purchase with the U.S. if the Super Hornet has been excluded.

During a recent trip to Singapore, Sajjan met with the CEO of Lockheed Martin, which is eager to sell Canada its advanced, but often maligned, F-35 — a plane the Liberals promised not to buy during the last election.

A defence industry source with knowledge of the file said Lockheed Martin has sent a letter to the Liberal government, expressing interest in providing its jets as the "interim solution."

Defence Minister Harjit Sajjan unveiled the government's long-awaited vision for the Canadian Armed Forces last week. The new policy calls for the purchase of 88 new jet fighters but also says the government will continue to explore a stopgap purchase until the full fleet arrives. (Adrian Wyld/Canadian Press)

Sajjan dismissed the notion of making the stealth fighter the "interim" solution and seemed to place his faith in the trade dispute being settled.

"No, right now for us we need to fill this interim capability gap and keep on with these discussions with the U.S. government on this," he told CBC News. "We are going to be looking at other options as well. We are looking for this to be resolved by the U.S. Department of Commerce quickly, so we can get back to business."

During an appearance before the Commons defence committee late Tuesday, the country's top military commander also dangled that possibility.

"What I would tell you is that, as the minister has said, the option for the Super Hornet is still open," said Gen. Jonathan Vance.

Referring to Boeing, he said: "They're a bad partner now. Maybe they [could] become a good partner again."

New versus used

But if the dispute drags on, it is unclear what the Liberal government can do if both the Super Hornet and the F-35 are ruled out as the gap-filler.

Defence experts have suggested there is a remote possibility the U.S. could sell Canada refurbished F-18s, similar to the current CF-18s.

The Pentagon recently had modernized F-16s on the market, which the Polish air force considered but eventually declined. That would be an even more unlikely fit, since Canada has never flown the single-seat fighters, which were the backbone of the U.S. air force for decades.

The "interim" fleet is meant to fill the gap until the Liberal government decides on a permanent replacement for the CF-18s.

Conservative MP James Bezan, his party's defence critic, wants the government to proceed to an open competition to buy fighter jets. (Adrian Wyld/Canadian Press)

Conservative defence critic James Bezan said he doesn't understand why the Liberals are twisting themselves into knots for a temporary solution when they can simply proceed to the open competition they promised for the full fleet.

Sajjan said that is still in the cards, but federal procurement officials have said a competition could take up to five years to run.

"If you look at what other states, other countries are doing in their recent procurement to replace their tactical fighters, none of them are taking five years to do this competition," Bezan said.

"If you look right now, Denmark is doing theirs in two years; Belgium means to complete theirs right now in 18 months; and just earlier this week, Finland started their F-18 replacement program, and they plan to have their first deliveries in 2021 and the entire fleet replaced by 2025, which coincidentally is the same time that our life extension on our CF-18s run out."