AUGUSTA, Maine (AP) — Maine Democratic Gov. Janet Mills has signed a law setting up a legal framework for the sale of recreational marijuana to adults.

Her office said Thursday that the law will take effect in mid-September.

Maine voters approved of legalizing marijuana in a public vote in 2016, but sales have been long delayed.

Mills says her administration has worked quickly to implement the voter-approved law.

State officials say marijuana for adult recreational use could arrive in stores as soon as early 2020. Maine already has legal medical marijuana.

Municipalities could opt in or out of allowing marijuana sales. Only a handful of cities and towns have laid the groundwork for retail sales.