(Reuters) - Maine Governor Paul LePage on Tuesday said he had signed a measure legalizing the recreational usage of marijuana in his state after voters approved the move in a November ballot initiative.

With the signature, the country's northeastern-most state becomes the ninth to legalize recreational use of the drug.

LePage, a Republican who had opposed the idea, expressed reservations about how legalization would be implemented in a regular weekly interview with WMOV radio, in which he confirmed signing the legalization proclamation.

"There is nothing I can do until the legislature gives me money to set up the infrastructure," LePage said.

The law will allow adults aged 21 and older to use the drug in private, but not public places, and to possess up to 2.5 ounces (70.9 grams) of marijuana.

"Mainers will no longer be punished for using a substance that is safer than alcohol," said David Boyer, who led the legalization campaign, in a statement.

"We look forward to working with the legislature to ensure a timely implementation of Question 1, which will provide adults with a legal way to purchase marijuana from licensed and regulated businesses."

Nearby Massachusetts last month became the first state in the northeast to legalize recreational marijuana usage after a similar measure passed in a Nov. 8 ballot initiative.

An October poll by Gallup showed that 60 percent of Americans now support the legalization of recreational use of marijuana. Even more approve of the idea of legalizing marijuana for medical use, a step that 28 states have taken.

The drug remains illegal under federal law, and U.S. President-elect Donald Trump, who takes office on Jan. 20, has sent mixed signals about his views on it.

(Reporting by Scott Malone in Boston; Editing by Alan Crosby)