The  Justice Department said it will not seek to veto new state laws in Colorado and Washington that legalize the recreational use of marijuana, and it will not bring federal prosecutions against dispensaries or businesses that sell small amounts of marijuana to adults.

A department official stressed, however, that marijuana remains illegal under federal law, and that U.S. prosecutors will continue to aggressively enforce the law against those who sell marijuana to minors and to criminal gangs that are involved in drug trafficking.

Atty. Gen. Eric Holder described the Obama administration’s middle-ground approach to marijuana enforcement in a call to the governors of two states.

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Holder also sent new guidance to U.S. attorneys telling them to focus their prosecutions on certain federal priorities. They include preventing drug sales to minors and stopping traffickers from moving marijuana across state lines.

Under the new guidance, a marijuana dispensary will not be targeted by federal prosecutors solely because of its size or its volume, an official said.

This change could have an immediate impact in California and the other states where  medical marijuana is legal under state law.