In response, Justice Department spokeswoman Allison Price says the department is not going to speculate on the outcome of the various ballot initiatives in each of the states - Colorado, Washington and Oregon.
Peter Bensinger, a former head of the Drug Enforcement Administration, told reporters that it is important for the public to know the dangers of legalizing marijuana and for the Justice Department to address the issue now.
Among the participants at the press conference were former directors of the White House Office of National Drug Control Policy.
Federal law prohibits production, possession and sale of marijuana.
(Copyright 2012 by The Associated Press. All Rights Reserved.)