DENVER—Colorado’s governor has again asked for a federal response to the state’s recent marijuana legalization vote.

Democratic Gov. John Hickenlooper said in a letter to U.S. Attorney General Eric Holder that Colorado needs a response “as soon as possible” about how the Justice Department will respond to Colorado’s marijuana vote.

Voters in Colorado and Washington state voted last week to allow adults to possess small amounts of marijuana without a doctor’s recommendation. So far, the Just Department has said federal law stands, but that the measures are under review.

Colorado’s letter was dated Tuesday and released to the press Wednesday. Hickenlooper and Colorado Attorney General John Suthers also talked to Holder by telephone last week, with no signal whether the Justice Department would sue to block the marijuana measure.