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.

In the wake of marijuana legalization in Canada, the U.S. Customs and Border Protection have a main message for people crossing into the country: don't bring any pot into the U.S.