In a dramatic change in drug policy, the Justice Department said Thursday that it won't sue to stop the states of Colorado and Washington from allowing recreational marijuana use as it issued a sweeping national policy statement that outlines its top priorities for pot enforcement.

The action, welcomed by supporters of legalization, could set the stage for more states to legalize marijuana. Alaska is scheduled to vote on legalizing recreational use of marijuana next year, and a few other states plan similar votes in 2016.

Under the policy, the top investigative priorities range from preventing the distribution of marijuana to minors to preventing sales revenue from going to criminal enterprises, gangs and cartels and preventing the diversion of marijuana outside of states where it is legal under state law.

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Other top-priority enforcement areas include stopping state-authorized marijuana activity from being used as a cover for trafficking other illegal drugs and preventing violence and the use of firearms in the cultivation and distribution of marijuana. The top areas also include preventing drugged driving, preventing growing marijuana on public land and preventing marijuana possession on federal property.