At the White House briefing, Feb. 23, press secretary Sean Spicer responded to questions about the Trump administration's stance on enforcement of federal marijuana restrictions. (Reuters)

White House press secretary Sean Spicer said Thursday that he expects states to be subject to “greater enforcement” of federal laws against marijuana use, a move that could undercut the growing number of jurisdictions moving to legalize the drug for recreational purposes.

Spicer, speaking at a White House press briefing, said that President Trump sees “a big difference” between use of marijuana for medical purposes and for recreational purposes.

“The president understands the pain and suffering that many people go through who are facing, especially terminal diseases, and the comfort that some of these drugs, including medical marijuana, can bring to them,” Spicer told reporters.

Spicer said that state’s allowance of marijuana for recreational purposes “ is something the Department of Justice, I think, will be further looking into.”

The Department of Justice declined to comment on Spicer’s remarks on Thursday afternoon following the briefing.

As of the beginning of the year, seven states and the District had adopted laws legalizing marijuana for recreational use.

In 2013 — as states took up the issue of legalizing marijuana — then-Deputy Attorney General James Cole issued a memo reiterating that the Justice Department would continue to enforce federal drug laws.

But Cole said that in places that legalized marijuana, federal officials should look to the regulatory systems of states to determine whether they should intervene.

In states with robust systems, Cole wrote, federal officials should continue to leave the matter to local law enforcement. But states without such systems might face challenges from the federal government, he said.

Cole said the federal government’s priorities would include preventing distribution of marijuana to children and preventing cartels from getting their hands on revenue from marijuana sales.

Advocates of liberal marijuana laws have eyed the arrival of Attorney General Jeff Sessions with unease. The former Republican senator from Alabama has a long track record of speaking out against marijuana use.

In his confirmation hearings, Sessions acknowledged that disrupting states marijuana markets by enforcing federal marijuana laws could create a strain on federal resources. But he said he “won’t commit to never enforcing the law.”

Washington Attorney General Bob Ferguson, whose state was among the first to authorize recreational use of marijuana, said in a statement Thursday that he was “deeply disappointed” to hear Spicer’s comments and noted his earlier call for a meeting with Sessions to discuss the matter.

“My office will use every tool at our disposal to ensure that the federal government does not undermine Washington’s successful, unified system for regulating recreational and medical marijuana,” he said.

In explaining the rationale of greater enforcement of federal marijuana laws, Spicer cited growing problems with other illicit drug use.

"I think that when you see something like the opioid addiction crisis blossoming in so many states around this country, the last thing we should be doing is encouraging people," Spicer said. There is still a federal law that we need to abide by."

In a statement Thursday afternoon, the National Cannabis Industry Association took issue with that argument.

"Science has discredited the idea that marijuana serves as any kind of gateway drug, and the addiction and death rates associated with opioids simply do not occur in any way with cannabis," said Aaron Smith, the organization's executive director.

He also argued that the current state programs are well-regulated and operating well.

In a separate statement Thursday, the Marijuana Policy Project pointed to polling showing a strong majority of voters opposed to the government enforcing federal prohibition laws in states where marijuana is legal for medical or adult use.

“The vast majority of Americans agree that the federal government has no business interfering in state marijuana laws,” said Mason Tvert, the group’s communications director. “This administration is claiming that it values states’ rights, so we hope they will respect the rights of states to determine their own marijuana policies.”

An array of marijuana industry executives also spoke out against Spicer's comments, including Danny Davis, managing partner of Convectium.

"We are hopeful that Mr. Spicer’s comments are not representative of the entire administration," Davis said. "Many of the states who helped elect President Trump just voted to also support recreational marijuana; it is hard to imagine that he would push an agenda with the support ratings where they are."

Voters in California, Maine, Massachusetts and Nevada just approved recreational marijuana use. Here's what they can learn from Washington, Colorado and Oregon, states where marijuana use has already been legalized. (Daron Taylor,Danielle Kunitz/The Washington Post)