Canadian cannabis company Aphria Inc (APH.TO) said on Thursday it was exploring strategic alternatives, including a sale, for its U.S. business, amid tightening enforcement of federal cannabis laws in the country.

Earlier this year, the U.S. Department of Justice revoked an Obama administration policy that discouraged federal prosecutors from pursuing marijuana-related crimes in states that had legalized the drug.

While states such as Colorado and California have legalized marijuana, there is sill a federal ban in place. Canada is expected to legalize pot in July.

Canadian securities regulators in October asked U.S.-linked marijuana firm to clearly warn investors about the risks, given the ban.

Leamington, Ontario-based Aphria makes and sells medical cannabis and its U.S operations are in Florida and Arizona.

On Monday, the company offered to buy rival Nuuvera Inc for $826 million, as it bets on a raft of medical cannabis approvals around the world over the coming years.