A consignment of armored vehicles has left Canada for Saudi Arabia despite Prime Minister Justin Trudeau's declaration that Ottawa was ready to halt a $13 billion arms deal with Riyadh.

Military manufacturer General Dynamic Land Systems Canada has been contracted to deliver 742 armored vehicles to the kingdom whose war on Yemen has recently come under increased scrutiny.

Canada has been exporting arms to Saudi Arabia based on the 2014 contract won by the Canadian unit of US weapons maker General Dynamics Corp.

On Sunday, a cargo ship loaded with armored vehicles left the port of Saint John for Saudi Arabia, a day after protesters gathered in the rain and fog to condemn the shipment, Canada's leading daily the Globe and Mail reported.

The protesters held signs and passed out pamphlets detailing concerns about the Saudi-led war in Yemen, which the United Nations has called the world’s worst humanitarian crisis, the paper said.

The cargo was apparently delayed for a day after longshoremen refused to cross the protest line, forfeiting their day’s wages, it added.

The longshoremen, the paper said, could face repercussions from their employer for their decision not to cross the protest, even though the combat vehicles were eventually transported.

The shipment came even though Trudeau said in October that Canada was ready to halt the arms deal with Saudi Arabia if it concluded the weapons had been misused.

"We strongly demand and expect that Canadian exports are used in a way that fully respects human rights," Trudeau said in the parliament.

"We have frozen export permits before when we had concerns about their potential misuse and we will not hesitate to do so again," he added.

His remarks, however, drew a warning from General Dynamics Corp which warned Canada against stopping the sales.

"Were Canada to unilaterally terminate the contract, Canada would incur billions of dollars of liability to General Dynamics Land Systems-Canada," it said.

David Perry, defense analyst at the Canadian Global Affairs Institute, called the warning “unusual” at the time.

He said General Dynamics Land Systems-Canada would normally keep a very low profile. "I can't imagine they are anything other than extremely worried," he said.

Trudeau, himself, had previously acknowledged that there would be “huge penalties” if Ottawa turned its back on the deal.

The Canadian premier, known for trying to portray himself as a human rights advocate, has been under pressure to scrap the deal inked by the previous government.

Besides killing tens of thousands of people, the Saudi war has brought the impoverished country close to the edge of a nationwide famine.