LAS VEGAS (AP) — A federal prosecutor has snuffed out plans by pot fans to celebrate Nevada’s new recreational marijuana law by lighting up on a Native American reservation near Las Vegas.

U.S. Attorney Daniel Bogden took a hard line in a letter to organizers of a cannabis festival this weekend, saying federal law applies and pot smokers could be prosecuted.

Bogden’s warning raised concerns about a possible Trump administration crackdown on marijuana.

Bogden said a 2013 Obama administration directive that was seen as relaxing enforcement on tribal lands in states where pot is legal might have been misinterpreted. He said pot is still illegal on tribal lands and on federal land.

Organizers of the High Times Cannabis Cup festival said there will still be music, T-shirts and souvenirs at the event at a Moapa Band of Paiutes festival site.

But spokesman Joe Brezny said it’ll essentially be just a concert this year.