Matthew Harvey wants to take his three-year-old daughter Lika to Disneyland in California, but after being banned from the United States for the rest of his life, that task isn't going to be easy.

Harvey has not been excluded for having a criminal record, or for trying to smuggle drugs into the U.S. He's being punished for providing a seemingly harmless answer to a question posed by the U.S. Customs and Border Protection service.

"They said that I was inadmissible because I admitted to smoking marijuana after the age of 18 and before I'd received my medical marijuana licence," he said.

"Of course I'd smoked marijuana, Canada didn't even have a program back then. I smoked marijuana recreationally. I guess I should have basically lied because now I am inadmissible apparently," he added.

Harvey's woes began in 2014 when he was 37. He was driving from Vancouver to Seattle for a concert when a customs officer noticed a marijuana magazine in his car.

Detained for 6 hours

He was pulled in for questioning and says he was detained for six hours, during which he was questioned about his marijuana use. A legal medical marijuana user in Canada, who was driving into a state where recreational and medical use of the drug is also legal, Harvey thought nothing of telling the truth.

But while Washington state may have legalized pot, it is still a federal controlled substance and therefore under the same purview as the border: the U.S. federal government.

For the rest of his life, Harvey must now apply for advance permission to enter the U.S. as a non-immigrant. The travel waiver, which costs $585 US ($750 Cdn), is granted on a discretionary basis, which means it may be good for a year, or two, or five, depending on the discretion of the approval officer.

When the waiver expires, Harvey will have to apply again and pay the fee, again, which is going up to $930 US ($1,200 Cdn) later this year.

A better way forward

As Canada prepares to legalize and regulate weed, Public Safety Minister Ralph Goodale says that Canadians should be "well advised to understand" that the U.S. is entitled to enforce whatever laws it deems fit.

The minister also said that there are ongoing discussions between Canada and the U.S. on a range of issues and coming up with a better approach to dealing with pot is always on the agenda.

"The present marijuana regime that has existed now for many years in both Canada and the United States has clearly failed Canadian and American young people because North American teenagers are among the biggest users of marijuana in the western world," Goodale said.

"We will certainly work very hard to make sure that they understand that we're moving a regime with respect to marijuana that will be far more effective than theirs," he added.

Options at the border

Len Saunders, an immigration lawyer with a practice in Blaine, Wash., who has been employed by a number of banned Canadians to process their waiver application says he expects Canada's plan to legalize pot will create a "boom" in his business.

"I think more people are going to purchase (pot) when it's legal in Canada and then … when they enter the U.S. and admit that they've purchased it legal in Canada they are still going to be denied entry until they (get) a waiver."

Prime Minister Justin Trudeau publicly admitted in 2013 to smoking marijuana "five or six times" in the past, including during his time as an MP. That won't likely cause him problems, at least for now, says Saunders.

"Prime Minister Trudeau would be admissible under a diplomatic passport, but private citizen Trudeau would not be admissible and would need a waiver for the rest of his life" if he was sanctioned for that past use, Saunders says.

Saunders' advice to Canadians asked about their past marijuana use at the border is to refuse to answer the question. They may be held for several hours, but there is no legal requirement, he says, to answer the question.

Harvey, who is now facing the lengthy and costly process of obtaining a waiver to make his daughter's dream of going to Disneyland come true, has different advice.

"We should raise awareness that if you are crossing over the border, not to admit to using recreational marijuana. Just deny, deny, deny," he said.