President Donald Trump’s pick to lead the Department of Justice wants marijuana to stay illegal at the federal level. But he doesn’t have a plan for how to make states abide by that law.

“We should either have a federal law that prohibits marijuana everywhere — which I would support, myself, because I think it’s a mistake to back off on marijuana,” William Barr told the Senate Judiciary Committee Tuesday afternoon in response to questions about his future role as attorney general. “I think current situation is untenable. It's almost like a backdoor nullification of federal law."

But Barr also said he wouldn’t try to stop marijuana’s success in the states that have already legalized the drug in the face of current federal law. If the government wants to allow states to go their own way on marijuana, Barr added the feds should go about that the “right way,” although he didn’t clarify what that means.

When asked by Sen. Kamala Harris if he would use federal resources to go after companies working within their state’s legal marijuana industry, Barr said that he wouldn’t. But he added that the U.S. “can’t stay in the current situation,” where a dichotomy exists between state and federal law.

“Can an existing administration and an attorney general start cutting deals with states and say well, ‘We’re not going to apply the law?’” Barr asked, using gun control as an example. Barr’s has a history of hardline views on drug use and supporting “tough-on-crime” policies. As the attorney general under George H.W. Bush in the early ‘90s, he authored a report titled The Case for More Incarceration, which argued for a more robust prison system and noted that prisoners on early release sometimes went on to commit new crimes, primarily relating to drugs.

Sen. Cory Booker brought up that report as support that Barr’s views on incarceration and criminal justice were antiquated. But Barr countered that the report was only meant to apply to “chronic violent offenders and gun offenders.”

Booker also noted that Barr has also resisted federal prison reform — which Congress recently passed — to primarily benefit non-violent drug offenders, many of whom are people of color. In prepared remarks released Monday, however, Barr said he’d “diligently implement” the new federal prison reform law while continuing to “keep the pressure on chronic, violent criminals.” "I think when you have violent gangs in the city killing people, murder and so forth and so on, sometimes the most readily provable charge is their drug trafficking offenses rather than proving culpability of the whole gang for murder,” Barr said on Tuesday. “So you can take out the whole gang on drug offenses, and you could be taking out a lot of violent offenders.”