Attorney General-designate, Sen. Jeff Sessions, R-Ala. testifies on Capitol Hill in Washington, Tuesday, Jan. 10, 2017, at his confirmation hearing before the Senate Judiciary Committee. 

(AP Photo/Andrew Harnik)

Asked if he would prosecute marijuana cases as attorney general, President-elect Donald Trump's choice for that post, Sen. Jeff Sessions, R-Ala., sidestepped the question during a Senate confirmation hearing on Tuesday.

"I won't commit to never enforcing federal law," Sessions told Sen. Patrick Leahy, D-Vt. "But absolutely it's a problem of resources for the federal government."

Sessions is an outspoken critic of marijuana, which is illegal under federal law but legal for recreational or medical use in nearly 30 states -- including Colorado. The spectre of an unfriendly federal government has industry advocates and local government leaders worried as Trump is set to take office.

The Obama administration has taken a hands-off approach to the recreational use of the drug in states that have strong regulatory systems. As attorney general, Sessions could reverse his predecessors' policies and instead clamp down on marijuana. In his comments Tuesday, Sessions did allow that some of the existing policies were "truly valuable" in determining which cases to prosecute. 

One marijuana expert, Sam Kamin, a law professor at the University of Denver, said Sessions is keeping his options open.

"He tried very hard, it would seem, not to commit himself in either direction," Kamin said. "He neither said that he approved of the Obama administration approach nor that he would set about undoing it."

Sessions added that if Congress wants the possession and distribution of marijuana to be legal, it's up to that body to change the law.

"It's not so much the attorney general's job to decide what laws to enforce. We should do our job and enforce laws effectively as we're able," he said.

An industry advocate, Kristi Kelly of the Marijuana Industry Group, said Sessions' comments gave her reason for optimism.

"His comments were not, 'let's rip everything apart and start tearing down doors and wreaking havoc on the industry as a whole,' " she said.

"I think there were some cues here than can help us understand what to expect," Kelly added.

About $1.1 billion in marijuana was sold in Colorado in 2016, with two months of data still to report. That's $2.8 billion in cumulative sales in the three years since recreational pot was legalized. Statewide, there are 30,866 employees registered to work in marijuana businesses as of December 2016.