States that have approved the use of recreational marijuana could be on a collision course with the federal government.

White House Press Secretary Sean Spicer said he suspects that President Donald Trump's Department of Justice won't be as lenient with pot-approving states as the previous administration.

'I do believe that you'll see greater enforcement of it,' he told a reporter asking about future action.

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White House Press Secretary Sean Spicer said he suspects that President Donald Trump's Department of Justice won't be as lenient with pot-approving states as the previous administration.

Voters in eight states and the District of Columbia have legalized marijuana for recreational use in direct violation of federal law.

Barack Obama instructed his Justice Department not to prosecute them. Trump has not said how his attorney general will handle the issue.

As a candidate, Trump said the federal government should 'leave it up to the states' to decide how to handle pot.

Yet, he also said at a conference in June of 2015 that he saw 'big problems' with the way the law was being applied in Colorado.

'If they vote for it, they vote for it,' he said. 'But, you know, they have got a lot of problems going on right now in Colorado.'

Six months later Trump had changed his tune, saying at rally in Nevada, where marijuana is also legal, that he wanted to study the issue.

'There's a question as to how it's all working out there, you know? That's not going exactly trouble-free. So I really think that we should study Colorado, see what's happening,' the Republican stated.

After Washington and Colorado voted yes on referendums to legalize the substance, Barack Obama's Department of Justice chose not to go after them.

'We've got bigger fish to fry,' he said in a Dec. 12, 2012, interview with Barbara Walters. 'It would not make sense for us to see a top priority as going after recreational users in states that have determined that it's legal.'

Obama said he did not, at that point, support legalization and noted that it's a 'tough' topic because it's the legislative branch that sets the laws.

'I head up the executive branch; we're supposed to be carrying out laws,' he said. 'And so what we're going to need to have is a conversation about, how do you reconcile a federal law that still says marijuana is a federal offense and state laws that say that it's legal?'

It took his administration until August of the following year to formally announce that it was 'deferring its right' to challenge legalization laws at that time.

'But if any of the stated harms do materialize—either despite a strict regulatory scheme or because of the lack of one—federal prosecutors will act aggressively to bring individual prosecutions focused on federal enforcement priorities and the Department may challenge the regulatory scheme themselves in these states,' a memo said.

Barack Obama instructed his Justice Department not to prosecute them. Trump has not said how his attorney general will handle the issue

Trump's attorney general, Jeff Sessions, must now decide, along with the president, whether he will follow in Eric Holder's footsteps or strictly enforce the law.

The president campaigned on a law and order platform but has copied Obama on some aspects of department prioritization, telling Justice and Homeland Security, for instance, that they should put their resources toward deporting criminal aliens over other illegal residents.

Trump could also decide that DOJ has 'bigger fish to fry,' as Obama said, and leave pot-passing states alone.

Spicer said Thursday that it was a question for the Department of Justice.

At the same time he made it clear to reporters that the Trump administration would abide by the intent of 2014 amendment that meant to end the prohibition on medical marijuana.

'That's very different than the recreational use, which is something the Department of Justice I think will be further looking into.'

Asked about medical marijuana, Spicer said, '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.'

He suggested that the administration would take a different approach to recreational marijuana use, comparing it to the opioid addiction crisis sweeping across the country.

'The last thing we should be doing is encouraging people,' he said. 'There is still a federal law that we need to abide by...when it comes to recreational marijuana and other drugs of that nature.'