US Attorney General Jeff Sessions, a fervent opponent of marijuana legalization, on Thursday reiterated that the federal pot prohibition exists but noted states have the right to pass their own laws.

Massachusetts voters almost two years ago voted to broadly legalize marijuana for recreational use for adults 21 and over, though the specific timeline for the opening of retail pot shops, expected sometime this year, remains unclear.

Home-growing and gifting of certain amounts of marijuana have been legal at the state level since December 2016.

A reporter asked Sessions about the federal stance amid legalization in Massachusetts.

Sessions, appearing in Boston for a press conference on arrests of people charged with benefit and federal document fraud, said the US Department of Justice will continue to enforce federal law on marijuana.

"Personally, my view is that the American republic will not be better if there are marijuana sales on every street corner, but states have a right to set their own laws and will do so, and we will follow the federal law," he said.

After the press conference, a Department of Justice spokesperson said the comments did not represent a shift for Sessions.

In January, Sessions announced that he was rescinding Obama-era rules that largely left states alone on marijuana legalization issues.

But as Massachusetts regulators sifted through marijuana business applications, US Attorney Andrew Lelling, a top federal prosecutor who reports to Sessions, issued a statement that regulators interpreted as the Obama-era rules continuing to be in effect.

Lelling said in the statement his office will continue to prioritize prosecutions to stop the opioid epidemic. Three marijuana-related areas that will be on his office's agenda include overproduction that could lead to illegal sales in other states, pushes of the drug to people under the age of 21, and the involvement of gangs like MS-13 in the drug trade.

The chairman of the Cannabis Control Commission said earlier this month Lelling's comments were similar to the Obama-era rules.

"I think it's good," Steve Hoffman, the chairman, told reporters. "I think it's helpful to have clarity, I think it's good to hear that his concerns are things we're already concerned about and addressing in our regulations, so I thought it was all good news."

This post was updated with a comment from the Department of Justice.