Spicer's statements at a White House news conference seemed to foreshadow a crackdown on state-legal marijuana operations, while drawing a distinction between medicinal- and adult-use programs.
President Donald Trump has said previously he believes in medical marijuana "100 percent" and in states' rights. But his Attorney General, Jeff Sessions, is an avowed foe of cannabis.
Following the November election, eight states plus Washington, D.C., have recreational-marijuana laws, while a total of 28 states and D.C. now have either recreational or medical.
Spicer's comments could be good news for Arizona's medical-marijuana program.
Arizona's medical-marijuana law, approved by voters in 2010, has more than 100 dispensaries and about 115,000 state-authorized patients.
The state's voters rejected a recreational marijuana proposal in November even as voters in California, Maine, Massachusetts, and Nevada approved legalizing marijuana for all adults 21 and older.
Roby Brock of Talk Business and Politics in Arkansas asked the question today on the minds of many: What will Trump and Sessions do?
Spicer began by drawing a sharp distinction between recreational and medical marijuana.
"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."
He added that "there is still a federal law that we need to abide by ... when it comes to ... recreational marijuana and other drugs of that nature."
Spicer then went on to explain that regulated medical marijuana was okay. He referred to legislation that prevented the Justice Department from using funds to target medical-marijuana businesses.
Recreational, he said — "that's a very, very different subject."
After a follow-up question, he said, "I do believe that you’ll see greater enforcement of it," and again talked about the "distinction" between medical and recreational use.
Demitri Downing, executive director of Arizona's Marijuana Industry Trade Association, said he was "thrilled" by Spicer's statements.
"Sounds like the president is going to respect the will of our voters, our states rights, and the fantastic medical marijuana system that we have in place!" Downing wrote in an e-mail. The association represents a number of the state's 100-plus medical-marijuana dispensaries.
Downing warned that, "I am not sure what this means for states like California and Colorado."
The national Marijuana Policy Project released a statement about Spicer's comments, noting that enforcement action would run against the wishes of state voters.
A survey released earlier today by Quinnipiac University found strong opposition to federal action against state-legal marijuana operations, the MPP's statement pointed out.
"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," said Mason Tvert, MPP spokesman. "It is hard to imagine why anyone would want marijuana to be produced and sold by cartels and criminals rather than tightly regulated, taxpaying businesses."
It was "critical," he said, that Congress continue to exclude medical marijuana from enforcement, "and we are hopeful that they will also adopt a provision that extends that principle to all state marijuana laws."