By Anita Kumar and Rob Hotakainen

President Donald Trump's administration said on Thursday for the first time that it will crack down on marijuana sales in states that have approved recreational pot use.

White House press secretary Sean Spicer said the Department of Justice will pursue enforcement of federal law against recreational use, but not medical use. The statement marked a major break with the Obama administration's hands-off approach to the growing marijuana legalization movement.

"I do believe that you'll see greater enforcement," Spicer told reporters at his daily briefing. "Because again there's a big difference between the medical use that's very different than the recreational use, which is something the Department of Justice will be further looking into."

The decision is certain to provoke a fight with the states that have legalized recreational marijuana. Those states are Alaska, California, Colorado, Massachusetts, Maine, Nevada, Oregon and Washington and the District of Columbia.

Jay Inslee, Washington state's Democratic governor, made it clear earlier this month that the state would fight hard if the Trump team tried to block its recreational pot sales. "I think it would be a really big mistake for them to pick this fight, and I hope it will not occur," Inslee said.

California legalization could translate to $5 billion in annual retail sales if Trump doesn't intervene, according to estimates from Marijuana Business Daily. A cannabis caucus formed in Congress last week and vowed to fight Trump, if necessary, and protect legalization. Among the co-founders is Rep. Dana Rohrabacher, a California Republican and Trump supporter whose name was floated for secretary of state before ExxonMobil CEO Rex Tillerson got the job.

Nevada Senate Majority Leader Aaron D. Ford called on the state's attorney general to "vigorously defend" the state's laws.

"Not only did voters overwhelmingly vote to approve the legalization of recreational marijuana, the governor's proposed education budget depends on tax revenue from recreational marijuana sales," Ford said. "Any action by the Trump administration would be an insult to Nevada voters and would pick the pockets of Nevada's students."

Seventy-one percent of voters say the government should not enforce federal marijuana laws in states that have legalized medical or recreational marijuana use, according to a Quinnipiac University Poll released Thursday. Fifty nine percent support legalizing recreational marijuana while 93 percent of Americans support medical marijuana use.

Washington and Colorado were the first states to legalize marijuana in 2012, while California followed suit last year. Twenty-eight states have legalized the drug for medical use.

Spicer compared the use of recreational marijuana to the opioid addiction crisis that has ravaged some communities across the nation. "The last thing we should be doing is encouraging people," he said. He referred specific questions on enforcement to the Justice Department.

But there's little evidence to connect marijuana to opioid addiction. In 2014, Johns Hopkins School of Public Health published a report that found in states that had legalized medical marijuana "the annual number of deaths from prescription drug overdose is 25 percent lower than in states where medical marijuana remains illegal."

"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 Taylor West, deputy director of the National Cannabis Industry Association.

Backers of marijuana legalization had been waiting to see how the Trump administration would respond to the growing conflict between state and federal marijuana laws.

Trump has voiced conflicting opinions about marijuana legalization through the years. At one point, during the presidential campaign, he said he supported allowing states to choose how to legislate medical marijuana. "In terms of marijuana and legalization, I think that should be a state issue, state-by-state," Trump told reporters in 2015.

But Trump's appointment of former Alabama Republican Sen. Jeff Sessions, a longtime marijuana foe who criticized President Barack Obama for not enforcing the ban on pots sales, rattled pot backers and had them braced for the worst. Obama, who smoked marijuana in his younger days in Hawaii, had left states to deal with the issue after famously telling ABC-TV's Barbara Walters in 2012 that he had "bigger fish to fry."

During his recent confirmation hearing, Sessions did not reveal whether he would enforce the laws. "Using good judgment about how to handle these cases will be a responsibility of mine," he said. "I know it won't be an easy decision, but I will try to do my duty in a fair and just way."

Marijuana advocates said Trump risks a public backlash if he cracks down on weed.

"If the administration is looking for ways to become less popular, cracking down on voter-approved marijuana laws would be a great way to do it," said Tom Angell, chairman of the pro-legalization group Marijuana Majority.

"The vast majority of Americans agree that the federal government has no business interfering in state marijuana laws," said Mason Tvert, director of communications for the Marijuana Policy Project. "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."

But Kevin Sabet, president of the anti-legalization group Smart Approaches to Marijuana, called the current situation "unsustainable."

"States that have legalized marijuana continue to see a black market for the drug, increased rates of youth drug use, continued high rates of alcohol sales, and interstate trafficking, with drug dealers taking advantage of non-enforcement," he said. "This isn't an issue about states rights _ it's an issue of public health and safety for communities."

Still, some industry officials said it was hard to take the White House announcement seriously, given the growing popularity of marijuana and widespread pubic acceptance for legalization.

"I don't think it's realistic for Trump to wage an all-out war against recreational marijuana. My guess is that this is saber rattling," said Aaron Herzberg, partner and general counsel of Calcann Holdings LLC, a California medical marijuana real estate company.

Spicer said the administration would not go after medical marijuana use.

"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 said.

(c)2017 McClatchy Washington Bureau