Prime Minister Justin Trudeau says suspending the federal permits that allow the export of a massive sale of armoured vehicles to Saudi Arabia would be a way to put pressure on Riyadh to offer more details on what really happened to slain dissident journalist Jamal Khashoggi.

This is the fourth iteration in four days of Mr. Trudeau’s position on what action, if any, Canada might take in response to the killing of Mr. Khashoggi, who disappeared on Oct. 2 after he entered Saudi Arabia’s consulate in Istanbul to get marriage documents. Saudi Arabia’s public prosecutor now says the murder of Mr. Khashoggi was premeditated.

On Monday, Mr. Trudeau said Canada is willing, if necessary, to suspend shipments in the $15-billion sale of weaponized light armoured vehicles (LAVs) to Riyadh, but on Tuesday he appeared to rule out cancelling the contract, saying it would incur a $1-billion penalty. On Wednesday, the Prime Minister expanded on what measures he could take, saying Canada is looking at suspending LAV shipments.

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On Thursday, the Prime Minister offered insight into why he might freeze LAV shipments, saying Canada is considering suspending these permits as a means of pressing Riyadh. Germany has already announced it is freezing arms exports to the Saudis.

“It provides us with a lever to require more answers from Saudi Arabia,” Mr. Trudeau said of suspending export permits for the LAV deal.

Still, Mr. Trudeau continued to resist calls to outright cancel the Saudi LAV deal, warning of penalties that would be borne by taxpayers.

Related: Turkey’s Erdogan urges Saudis to reveal who ordered Khashoggi’s killing

Who killed Jamal Khashoggi and why? Here’s what we know so far

Speaking to journalists during a visit with the Dutch Prime Minister, Mr. Trudeau raised his estimate of the cost of abrogating the LAV deal, now saying it could cost Canada several billions of dollars.

“Suffice it to say, possible penalties would be in the billions of dollars,” Mr. Trudeau said.

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He blames former prime minister Stephen Harper for signing an agreement with Riyadh that included such restrictions. The 14-year deal was signed in 2014 under Mr. Harper, but it was the Liberal government in 2016 that approved exports to the Saudis under Canada’s arms-export control program.

Mr. Trudeau on Thursday reiterated that the government is “right now actively reviewing” existing export permits as Canada and its allies look for ways to press Riyadh.

“We’re part of the international community that has serious questions for Saudi Arabia with respect to the behaviour of the Saudis in the murder of Jamal Khashoggi. Until we have answers, we will continue to seek means to exert pressure together on Saudi Arabia to ensure they understand the importance of respecting human rights and freedom of the press.”

The Prime Minister’s remarks come as the Liberal government faces mounting pressure from human-rights groups for Canada to curb business ties with Saudi Arabia over Mr. Khashoggi’s suspicious death.

Saudi Arabia’s ruling monarchy originally denied any wrongdoing in early October but three weeks later said the journalist had died in a fist fight with government officials.

On Thursday, the Saudi story shifted again as Saudi Arabia’s public prosecutor said the killing of Mr. Khashoggi was premeditated, citing a joint Saudi-Turkish investigation, according to Saudi state media.

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Mr. Trudeau defended his hesitation to cancel the deal on Thursday. He was asked by a reporter why Canada wasn’t willing to pay huge penalties to scrap the LAV deal agreement when it recently wrote off a major auto loan. The CBC reported earlier this week that the federal government had quietly written off a $2.6-billion auto-sector loan that was advanced to Chrysler during the 2009 economic meltdown. This remaining loan value reportedly included $1.1-billion in principal plus interest.

The Liberal Leader said he had nothing to do with the auto company loan, blaming it on Mr. Harper, who was prime minister in 2009. “This is a decision that Stephen Harper made to pay Chrysler and not have any chance of ever recovering that loan.”

Mr. Trudeau said his government is still consulting with other international allies on a plan to persuade Saudi Arabia to come clean on what happened to Mr. Khashoggi.

“Canada is committed to upholding human rights, freedom of expression and the protection of journalists around the world,” he said. “We condemn the horrible murder of Jamal Khashoggi and are deeply concerned on the participation of Saudi officials.”

Roland Paris, a former foreign-policy adviser to Mr. Trudeau, offered on Thursday what appeared to be a defence of the Prime Minister’s hesitation to cancel the Saudi LAV deal. “I can’t talk about the contract, but there’s a reason why I went from calling for its cancellation before my stint in the PMO, to saying little about it since then: I learned its contents,” Mr. Paris said via Twitter.

In the Commons on Thursday, the opposition NDP urged the Liberals to act. “Everyone knows the kingdom is one of the worst human-rights offenders in the world. This alone should be enough. What are the Liberals waiting for?” NDP foreign affairs critic Hélène Laverdière said.

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On Thursday, European parliamentarians voted 242 to 23 for the suspension of weapons sales to Saudi Arabia, but the resolution is non-binding. Many European countries are still weighing their options.

Spain’s Prime Minister said earlier this week his government would fulfill past arms-sales contracts with Saudi Arabia despite his “dismay” over the “terrible murder” of Mr. Khashoggi.

In London, British Prime Minister Theresa May also rebuffed a call from opposition lawmakers to end weapons sales to the Arab kingdom, telling Parliament on Wednesday “the procedures we follow are among the strictest in the world.”

With reports from Reuters and Associated Press