Canada legalized marijuana this week, but what does that mean for Americans who want to engage in a little "pot tourism" and perhaps bring back a small, green souvenir? Are border patrol agents really going to bust you for a joint or dime bag?

The short answer is that you would be taking a risk. You could either face years in jail or stiff fines, or have your memento thrown away or confiscated.

"U.S. Customs and Border Protection enforces the laws of the United States and U.S. laws will not change following Canada’s legalization of marijuana," a Customs and Border Patrol spokesperson told NBC News in a statement.

But what actually happens to you if you are discovered possessing marijuana is up to the officer you encounter.

"Determinations about admissibility and whether any regulatory or criminal enforcement is appropriate are made by a CBP officer based on the facts and circumstances known to the officer at the time," the spokesperson said.

Justin Strekal, a spokesman for NORML, a DC-based nonprofit marijuana advocacy group, told NBC News, "While our polite neighbors to the north had the good foresight to end the senseless criminalization of marijuana, the U.S. has not — and thus, travelers should not attempt to transport cannabis across the border."

American tourists returning will face an interview and are also subject to search, said Nick Hentoff, a criminal defense attorney in New York. He said he wouldn't recommend trying to bring back any pot from Canada.

"It's not a good idea," he told NBC News. "They're on the lookout."

Marijuana remains a Schedule 1 drug, on a par with heroin. In 2017, nearly 700,000 Americans were arrested for marijuana-related crimes, 90 percent of which were for possession offenses.

However, there has been some relaxing of marijuana offenses at the local level. You can purchase pot in Washington state and Colorado, but you must consume it in private and away from a public space. In New York City, the police department now issues tickets for smoking marijuana in public instead of conducting arrests.

In June, President Donald Trump said he would support a bill to end the federal pot ban and defer judgment to each state. That's in contrast to the stance of Attorney General Jeff Sessions, who has vowed to enforce federal marijuana laws.