The United States reacted cautiously on Saturday to a Mexican measure that would make it legal to carry small amounts of cocaine, heroin and other drugs for personal use.

News of the decriminalization did not make the front pages of any major Mexico City newspaper, nor was it discussed in editorials. It was slightly better publicized in the north of the country, where turf wars between rival drugs gangs have caused hundreds of killings along the Mexico-U.S. border, but was still overshadowed by news about immigration.

President Vicente Fox has yet to sign the bill, which would eliminate penalties for those caught with small amounts of some drugs, but his office has applauded it.

Mexican lawmakers have said the bill will let authorities focus on major drug traffickers and not clutter prisons with small-time offenders.

U.S. Embassy spokeswoman Judith Bryan said Saturday the measure could actually make it easier to prosecute drug crimes because it attempts to "precisely specify the amount of narcotics in possession of a suspect to allow a criminal prosecution."

"Preliminary information from Mexican legislative sources indicates that the intent of the draft legislation is to clarify the 'small amounts' of drugs for personal use as stated in current Mexican law," she said.

Mexican law already left open the possibility of dropping charges against people caught with drugs if they are considered addicts and if "the amount is the quantity necessary for personal use." The new bill drops the "addict" requirement — automatically letting any "consumers" have drugs — and sets out specific allowable quantities.

In Mexico City's stylish Zona Rosa neighborhood, Mexicans and tourists alike were surprised to hear it could soon be legal to carry small amounts of drugs.

Drug violence "will drop because there will be less pressure on the people who consume drugs," said Francisco Garrido, who was selling orange juice at a sidewalk stall.

But Berta Perez, an antique store owner, worried that drug sales would bring young budget travelers and spook away well-heeled tourists.

If signed by Fox, purchasing drugs "would be like buying a cigarette on the street," she said.

Washington has long praised the Fox administration for its anti-drug efforts.

Since the president took office in December 2000, several key drug lords have been captured, including Benjamin Arellano Felix, the suspected operations chief of a Tijuana-based drug gang bearing his family's name, and Osiel Cardenas, the accused head of the Gulf cartel, thought mainly to operate along Mexico's border with Texas.

Yet drug addiction is growing in Mexico, especially in border cities like Tijuana.

John Morgan, a retired school psychologist visiting Mexico City from Grand Junction, Colo., said it makes sense for the country to decriminalize marijuana — but that harder drugs maybe should not be included.

"We have put people in jails for years for marijuana, something that is probably less harmful than alcohol," he said. "But the list here is a little too global, there are several classes of drugs which are quite harmful."