During the first day of his confirmation hearings on Capitol Hill on Tuesday, Sen. Jeff Sessions did not provide much in the way of a definitive plan for how he would direct the Justice Department to treat states’ legalization of a drug that is very much illegal under federal law. Sessions, who in the past has been outspokenly opposed to legalized marijuana, admitted during questioning by his fellow U.S. senators that disrupting states’ legal marijuana markets by enforcing federal marijuana laws could create an undue strain on federal resources.

However, responding to a question from Democratic Sen. Patrick Leahy of Vermont, Sessions (a Republican representing Alabama) also said he “won’t commit to never enforcing federal law.”

Trump’s nomination of Sessions to be the country’s top lawyer last fall immediately raised questions about the future of a U.S. marijuana industry that brought in an estimated $6.7 billion in legal sales last year. Seven more U.S. states voted to legalize marijuana in some form on Election Day in November. In total, eight states have voted to legalize the drug recreationally and 29 states have legalized medical marijuana.

Under President Barack Obama’s administration, the legal marijuana industry has grown rapidly in the U.S. That’s due, in large part, to the fact that the Justice Department under Attorneys General Eric Holder and Loretta Lynch has generally declined to challenge states’ marijuana laws. And, in 2014, Congress passed a spending bill prohibiting the Justice Department from using federal funds to go after marijuana programs that comply with their respective state’s laws. (That bill remains in effect, though it needs to be renewed annually and could face a challenge from the new administration.)

While Donald Trump himself voiced his support for legal medical marijuana on the campaign trail, the Sessions nomination makes it unclear where Trump’s administration will stand on the question of statewide decisions to legalize the drug for either medical or recreational purposes. That uncertainty has been a cause for concern in the marijuana industry. In the past, Sessions has publicly stated his belief that “Good people don’t smoke marijuana.” The senator also said just last year that “we need grown-ups in charge in Washington to say marijuana is not the kind of thing that ought to be legalized… that it is, in fact, a very real danger.”

Earlier in the day, Trump spokesman Sean Spicer said in an interview that Sessions would follow Trump’s agenda as a member of the president-elect’s administration.

On Tuesday, Sessions was not quite as emphatic on the issue as he has been in the past. In reference to the guidelines issued by the Justice Department in 2013 that effectively left marijuana law enforcement up to individual states, Sessions told Sen. Leahy “some of them are truly valuable in evaluating cases, but, fundamentally, the criticism I think that is legitimate is that [the guidelines] may not have been followed.” Sessions went on to say he would need to use “good judgment” when deciding how to enforce federal marijuana laws, should he be sworn in as Attorney General, adding “I know it won’t be an easy decision, but I will try to do my duty in a fair and just way.”

Sessions also responded to a similar question from Republican Sen. Mike Lee by saying that “it is not the Attorney General’s job to decide what laws to enforce.”

In response to Sessions’ comments during Tuesday’s hearing, pro-legalization lobbying group the Marijuana Policy Project issued a statement in which the group’s Director of Federal Policies, Robert Capecchi, said the group is “cautiously optimistic” about the incoming administration’s intentions regarding marijuana. Capecchi also said in the statement: “It is notable that Sen. Sessions chose not to commit to vigorously enforcing federal prohibition laws in states that have reformed their marijuana laws. He also recognized that enforcing federal marijuana laws would be dependent upon the availability of resources, the scarcity of which poses a problem. He was given the opportunity to take an extreme prohibitionist approach and he passed on it.”