Call it pot purgatory.

Officials in the four most recent states to legalize marijuana — including Massachusetts and Maine — are languishing in limbo after signals from the Trump administration that a recreational marijuana market crackdown may be coming.

On the one hand, state leaders are mandated to follow the will of their voters, who approved legalization measures in November. But, on the other, it may not make sense to keep spending scarce taxpayer dollars building a new bureaucracy to regulate pot greenhouses, shops, and testing facilities, if national authorities will soon swoop in and snip the industry, which remains strictly forbidden under federal law.

On Tuesday, Massachusetts’ top marijuana regulator, Treasurer Deborah B. Goldberg, asked the Trump administration for an explanation of its intentions on the issue. Two weeks ago, a Trump spokesman predicted “greater enforcement’’ efforts against recreational marijuana, but provided no specifics.

US Senator Elizabeth Warren and some of her colleagues have also written to the Justice Department, requesting it leave the old policy in place, saying it is “essential’’ that states “receive immediate assurance from the DOJ that it will respect’’ their ability to enforce sensible drug policies.

In a letter sent to the Department of Justice Tuesday morning, Goldberg asked for clarity about whether Attorney General Jeff Sessions will go after the industry. Sessions has a long history of hard-line opposition to marijuana, and has noted that “it does remain a violation of federal law to distribute marijuana . . . whether a state legalizes it or not.’’

Goldberg said she’s aware of her obligation to manage state finances prudently.

“Fiscal responsibility requires predictability, and I want to ensure that we understand the DOJ’s intentions,’’ the Brookline Democrat wrote. “In recent weeks, comments from the Trump Administration suggest that the DOJ may be considering a change. I would greatly appreciate your prompt response to clarify whether this is true — and if so, what changes we should prepare for before we commit significant public resources to implementing Massachusetts’ recreational marijuana laws.’’

In a November referendum, Massachusetts voters legalized growing, buying, possessing, and using limited amounts of marijuana. But sales aren’t expected to be legal until summer 2018. In the meantime, while Goldberg readies a regulatory infrastructure, the Legislature is tinkering with the law.

In an interview, Goldberg said she feels her letter is speaking not just for Massachusetts, but also for other states facing the same sticky situation.

The federal government cannot undo what voters made legal — adults having and using pot. And they can’t make state or local police in Boston or Portland enforce federal law.

But they could go after recreational dispensaries in states where they are already up and running, such as Colorado and Alaska. And, experts say, such enforcement actions would chill the burgeoning markets in Massachusetts, Maine, California, and Nevada. After all, who would want to invest money in a pot shop that could soon be raided. And that raises questions about how much effort to put into creating an infrastructure to regulate such facilities.

“All the feds need to do is have the FBI go in and arrest one guy operating legally under state law — and that message will come across quite clearly,’’ said New York lawyer Marc J. Ross, who teaches about the intersection between state and federal marijuana laws.

“So purgatory is a good word’’ for the situation legalization states are in, he said.

Historically the federal government has refrained from enforcing federal marijuana law in states where voters made it legal. But if the GOP administration changes its policy, “it’s going to cause upheaval in not just the four states that just passed legalization, but also in the four other states where it’s been legal for longer.’’

(Marijuana for medical use exists in a different category, and the Trump administration has indicated that industry will not be targeted.)

Still, state officials are plowing ahead, saying they can’t wait for Washington; they are obligated to do what their constituents asked for.

Senator Tick Segerblom, a Democrat who represents downtown Las Vegas, said, “unless Trump sends in the federal troops,’’ the Silver State, in the middle of its legislative session, is going “full bore’’ to implement legalization.

“From a political perspective, I know Trump is an idiot, but if he goes after marijuana, he’s a true idiot,’’ Segerblom said, adding that the people who legalized marijuana in his state are Trump voters. “The marijuana voters are white, male, blue-collar voters who don’t necessarily want to use it, but don’t think anyone should stop people using it,’’ he said.

A spokeswoman for the Nevada Department of Taxation said it is required to implement the legalization ballot measure as passed.

And, said Stephanie Klapstein, “we will continue on that path unless something concrete happens at the federal level that results in a mandate for us to do otherwise.’’

Maine state Senator Roger Katz, who cochairs the state’s marijuana implementation committee, acknowledged there is a “dissonance’’ between talk from the White House and his state’s ballot question.

“If we knew that the Trump administration was going to definitively answer this question by a particular date, that would be one thing,’’ he said. “But there doesn’t appear to be any timetable and, in theory, the only answer might be silence.’’

So, said the Republican who represents Augusta and four other communities, Maine voters “expect us to go ahead and do the work we need to impose a regulatory and oversight system on this new industry.’’

The best solution, Katz said, would be to get clear guidance from Congress. But he doesn’t expect that to happen.

In California, too, there is worry and pushback. Lieutenant Governor Gavin Newsomwrote to Trump last month urging the government not to get rid of a regulated marijuana industry and hand the pot market back to “cartels and criminals.’’

Under President Obama, federal authorities effectively allowed the recreational marijuana industry to blossom in several states.

The government abstained from enforcement of certain parts of federal law through a memorandum issued by a top Justice Department official in 2013.​

That document, known as the Cole Memo, set enforcement priorities for federal prosecutors, such as preventing revenue from the sale of marijuana from going to cartels and preventing violence in the drug’s distribution.

But those priorities did not include prosecuting marijuana businesses operating in legal, regulated markets under state law, which gave the industry room to grow.

“To say there’s a tremendous amount of uncertainty is an understatement,’’ said Kevin Sabet, president of Smart Approaches to Marijuana, a nonprofit cofounded by former US representative Patrick Kennedy that opposes the legalization and commercialization of marijuana.

“Until there’s further clarity, if I were a state regulator, I would slow down the process of legalization until we figured out what the message of the feds would be.’’

Material from the Associated Press was used in this report. Joshua Miller can be reached at joshua.miller@globe.com.