Maine Gov. Paul LePage (R) on Friday vetoed a bill that would legalize the sale of recreational marijuana, nearly a year after residents voted to set up a system to sell and regulate the drug.

In a letter, LePage said the law would set up a bifurcated system of recreational and medical sales — which are legal in Maine — of marijuana in the state. Allowing all adults to purchase marijuana also would violate federal law, LePage said. The governor said that while the Obama administration said it would not enforce federal marijuana law, the Trump administration has said it has concerns about legal marijuana. LePage said he sought guidance from Attorney General Jeff Sessions on the matter.

“Until I clearly understand how the federal government intends to treat states that seek to legalize marijuana, I cannot in good conscience support any scheme in state law to implement expansion of legal marijuana in Maine,” LePage wrote.

LePage wrote that if the state were to create what amounts to a new industry in the state, “we need assurances that a change in policy or administration at the federal level will not nullify those investments.”