Canadians wanting to cross the U.S. border are being asked different marijuana questions than they were before cannabis was legal, a U.S.-based lawyer says.

Marijuana has been legal in Canada for a month already but immigration lawyers and cannabis executives say when it comes to getting into the United States, the worst may be yet to come.

Canadian officials have warned the public not to try to enter the U.S. with marijuana products.

The parliamentary secretary to Canada's Minister of Public Safety says Canadians who have used marijuana legally at home should "be honest and tell the truth" when they show up at the U.S. border next year.