A top official of the U.S. Customs Border Protection confirmed Wednesday that anyone working or investing in Canada’s cannabis industry will be treated as if they are an illegal drug trafficker.

Despite that Canada will have legal cannabis nationwide in a month, and that a majority of states have legalized cannabis to some extent, the plant remains illegal at the federal level. The U.S. government views foreigners working in the marijuana industry the same way they would someone working for an illegal drug cartel or as a dealer, regardless of their home nation’s laws.

Executive assistant commissioner for the Office of Field Operations for Customs Border Protection (CPB), Todd Owen said Thursday that agents will give Canadians a lifetime ban if they are connected to Canada’s legal cannabis sector.

“If you work for the industry, that is grounds for inadmissibility,” Owen told Politico. “We don’t recognize that as a legal business. Facilitation the proliferation of the legal marijuana industry in U.S. states where it is deemed legal or Canada may affect an individual’s admissibility to the U.S.” He noted that investors from countries like Israel have been denied entry into the U.S.

It was previously reported earlier this summer that admitting to smoking marijuana currently or in the past will can also result in a lifetime ban. He also noted that sniffing dogs can smell residue weeks after it’s been used so people crossing should not lie if the questions are asked.

“Our officers are not going to be asking everyone whether they have used marijuana but if other questions lead there – or if there is a smell coming from the car, they might ask,” Owen told Politico. “If you like about it, that’s fraud and misrepresentation, which carries a lifetime ban.”

Legal experts have been warning Canadians about the risks since the decision to legalize came in June.

“It’s basically black and white—if you admit to a U.S. border officer at a U.S. port of entry that you’ve smoked marijuana in the past, whether it’s in Canada or the U.S., you will be barred entry for life to the United States,” said Washington-state lawyer Len Saunders.

He added that rather than lie at the border, to just not reply. Refusal to reply will result in denial of entry for the day but not for life.

The commercial cannabis sector in Canada has already become a multi-billion dollar industry with more than 150,000 jobs expected to be created in the years to follow legalization. This is likely to cause a lot of problems for Canadians crossing the border.

“It’s going to happen even more, and especially now that they’re going after business travelers, it’s going to be the Wild West at the border. It’s going to be crazy” Washington-state immigration lawyer Len Saunders told the Vancouver Star in July.