By Susan Heavey

WASHINGTON, Dec 14 (Reuters) - U.S. President Barack Obama says federal authorities should not target recreational marijuana use in two Western states that voted to make it legal, given limited government resources and growing public acceptance of the controlled substance.

Obama's first comments on the issue come weeks after Washington state and Colorado voters supported legalizing cannabis last month in ballot measures that stand in direct opposition of federal law.

"It does not make sense from a prioritization point of view for us to focus on recreational drug users in a state that has already said that under state law that's legal," he told ABC News in part of an interview released on Friday.

"At this point (in) Washington and Colorado, you've seen the voters speak on this issue. And, as it is, the federal government has a lot to do when it comes to criminal prosecutions," Obama said.

Marijuana remains an illegal drug under U.S. federal law, but Washington and Colorado on Nov. 6 became the first states in the nation to make it legal for individuals to possess up to an ounce of marijuana for private use.

The Department of Justice has maintained that pot remains a federally controlled substance, and states have been looking for guidance from federal authorities on how they will handle the conflict with state laws.

Obama's comments do not mean that Justice Department officials have completed their review of the Colorado and Washington laws, a department spokeswoman said on Friday.

Asked whether Drug Enforcement Administration agents were arresting people for possessing pot in Colorado and Washington, spokeswoman Dawn Dearden said that the "DEA's focus has always been to disrupt and dismantle large-scale drug trafficking organization - not to arrest individual users."

Medical use of marijuana is legal in 18 U.S. states. But federal officials have still continued to crack down on some providers in those states.

DOJ TO RESPOND 'RELATIVELY QUICKLY'

Obama called the situation "a tough problem, because Congress has not yet changed the law." He told ABC that "what we're going to need to have is a conversation about" how to reconcile federal and state laws, and that he has asked U.S. Attorney General Eric Holder to examine the issue.

Holder has said the Justice Department is still considering its options but will act "relatively soon," possibly with a month.

"I think we will come up with a policy that will be respective of federal law but also will make sure we are effective in our fight against crime that truly has an impact on the American people," he said after a speech in Boston on Tuesday. He is scheduled to speak later on Friday at an event in Tulsa, Oklahoma.

Congress is also expected to weigh in soon. Senate Judiciary Committee Patrick Leahy has said he plans to hold a hearing soon after the next Congress convenes in January and called Obama's comments Friday "common sense."

"In a time of tight budget constraints, I want law enforcement to focus on violent crime," the Vermont Democrat said in a statement. "But now that we have a gap between federal and state laws on marijuana, we need more information and a wider discussion about where our priorities should be."

In a separate letter to the Office of National Drug Control Policy on Thursday, Leahy said lawmakers could reconcile that gap, but they need to know how the Obama administration plans to proceed. For example, Congress could amend the federal law to allow small amounts of marijuana in states where it is legal.

Several advocacy groups that back looser marijuana laws welcomed Obama's comments, even though it remains unclear how his administration will act.

Ethan Nadelmann of the Drug Policy Alliance said he is still worried Holder will act before considering the views of lawmakers and others.

The president's comments are "definitely a tentative step forward," said Nadelmann, whose advocacy group backs U.S. drug policy reform. "It suggests that he's keeping his options open to be a little more forward on this."

Still, Obama told ABC that he would not go so far as to say pot should be legalized altogether. There are also concerns about drug use in children and violence, the father of two told ABC, according to its website.

Obama himself admitted to regularly smoking pot in high school in his 1995 memoir, "Dreams of My Father," but has expressed regret.

"I want to discourage drug use," he told ABC. 

(Additional reporting by David Ingram, Alina Selyukh and Scott Malone)

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