WASHINGTON -- The Obama administration said it favors shorter jail sentences for crimes involving crack cocaine, a stance likely to spark a debate with law-enforcement officials who have opposed easing the penalties.

Under current law, a person caught with 500 grams of powder cocaine gets the mandatory minimum sentence of five years, while it takes only five grams of crack cocaine to trigger the same sentence. Critics of the law have long maintained that it unfairly targets African-American communities, where crack is more prevalent.

"The administration believes Congress's goal should be to completely eliminate the sentencing disparity between crack cocaine and powder cocaine," Assistant Attorney General Lanny Breuer, who heads the Justice Department's criminal division, testified Wednesday before the Senate Judiciary Subcommittee on Crime and Drugs.

Mr. Breuer said the punishments are fundamentally unfair, considering evidence showing little difference between the two forms of cocaine, plus the racial impact. He suggested the disparity should be eliminated by relaxing crack sentences, rather than by raising powder-cocaine penalties, as some have suggested.

The administration's stance reverses statements made by the Justice Department during the Bush administration, which opposed treating the two versions of cocaine the same. It's also the latest evidence from the administration and others that attitudes may be changing on handling the nation's drug problems.