President Trump said Friday that he is likely to support a bipartisan congressional effort to give states autonomy over their marijuana laws — a move that would put the White House in direct conflict with the Justice Department.

Trump was asked about a bill introduced Thursday by Sens. Cory Gardner (R-Colo.) and Elizabeth Warren (D-Mass.) that would protect the nine states and D.C. that have legalized marijuana from any federal interference. This would allow businesses that sell marijuana to operate without fear of prosecution by the Justice Department.

Trump told reporters that he supports Gardner and is considering backing the bill.

“I know exactly what he’s doing,” Trump told reporters as he prepared to leave the White House on Friday to a Group of Seven economic summit in Canada. “We’re looking at it. But I probably will end up supporting that.”

Trump’s attorney general, Jeff Sessions, has long been an impassioned opponent of marijuana, and in January the Justice Department rescinded Obama administration guidance that instructed federal law enforcement not to waste resources targeting marijuana operations in states where they are legal.

In scrapping what’s known as the Cole memo, Sessions unilaterally determined that the federal government should have the authority to crack down on marijuana sales.

As a candidate, Trump said marijuana legalization should be up to the states.

Since arriving in office, Trump has had a frosty relationship with Sessions, repeatedly criticizing him in public for having recused himself from overseeing the investigation into Russian interference in the 2016 presidential election.

On Thursday, Gardner said he had spoken with Trump and was confident the president would sign the bill.

“I have talked to the president about this bill,” Gardner said at a news conference. “In previous conversations he talked about the need to solve this conflict. He talked about his support for a states’ rights approach during the campaign. Not putting words in the mouth of the White House, but I think this will be an opportunity for us to fulfill what is that federalism approach.”