American officials have been quietly raising questions about whether Canada's marijuana legalization might slow traffic at the border, and are being told by their northern neighbours there's no reason that should happen.

The issue has come up in phone calls between high-level officials and again in passing this week during a first face-to-face encounter between Public Safety Minister Ralph Goodale and his U.S. counterpart, Homeland Security Secretary Kirstjen Nielsen.

It hasn't been contentious, he said.

"The only thing they say is, 'Will this cause lineups?'" Goodale said in an interview.

"And our answer is: Not unless you change your procedures. And there's no reason for you to change your procedures. Because the law with respect to the border hasn't changed one iota."

He said it came up briefly at the tail end of the meeting with Nielsen and in past phone conversations. Federal officials say there has been no attempt to pressure Canada — that the U.S. has expressed respect for Canada's sovereign decisions.

It's a far cry from the conversation of the early 2000s.

At that time, the Bush administration strenuously argued against marijuana decriminalization. And in the wake of the 9/11 attacks, public figures in both countries expressed alarm over anything that might cause additional border checks and worsen delays for cargo shipments.

Now the U.S. has nine states with legal marijuana and numerous others that have decriminalized it. And the border is more sophisticated. The Canadian view is that there's no reason for traffic snags — because it's just as illegal to transport pot across the border as it ever was.

"They do [raise it]. Because they know the Canadian law is changing," Goodale said.

"They're saying they don't anticipate any great change. But I think there is some concern that Canadian law is changing, and does that cause them to behave in a different way. The answer should be no."

There are still a few months before Canada's policy comes into effect. The government has projected it will take effect in July, but there are lingering doubts with the legalization bill facing heavy scrutiny in the Senate.

Goodale said the Canadian government also intends to work on public awareness of the rules, and the legal risks of bringing drugs to the U.S. border: "We'll make sure that the rules are clear," he said.