CINCINNATI (AP) — Former U.S. House Speaker John Boehner (BAY'-nur) says he has had a change of heart on marijuana and will promote its nationwide legalization.

Known as an avid cigarette smoker, the Ohio Republican has joined the advisory board of Acreage Holdings , a multistate cannabis company. The company also announced that former Massachusetts Gov. William Weld has joined its advisory board.

Boehner says in a statement his position "has evolved" from opposition to legalizing marijuana. He says he believes legalizing marijuana can be helpful to the nation's veterans and as a way to help fight the U.S. opioid drug crisis. He wants to see federally funded research done and to allow Veterans Affairs to offer marijuana as a treatment option.

Boehner also says the move would curtail federal-state conflict on marijuana policies.