The United States is up in arms over a proposed Mexican law that would decriminalise the possession of small amounts of drugs, including cocaine and heroin.

The law was approved by Mexico's Congress last week. Aspokesman for President Vicente Fox said that he would sign it into law to allow police to focus on the more important battle against violent drug gangs.

"The president is going to sign that law. There would be no objection," he said. "It appears to be a good law and an advance in combating narcotics trafficking."

American officials fear that the law will lead to an increase in drug tourism to Mexican border areas and increase US consumption of narcotics.

Eduardo Medina Mora, who as Public Safety Secretary heads Mexico's police force, met yesterday with Karen Tandy, head of the US Drug Enforcement Administration, although he said she had not been convinced about the need for the new law.

Senor Mora said that Senators had changed the law submitted by Senor Fox by introducing a table laying out the maximum amounts of each drug that could be legally possessed.

Under the law, consumers could legally possess up to 25 milligrammes of heroin, 5 grams of marijuana (about one-fifth of an ounce, or about four joints), or half a gram of cocaine.

Mexican law presently allows judges the latitude of dropping charges against people caught with drugs if they can prove they are addicts and if an expert certifies that they were caught with "the quantity necessary for personal use".

The new bill makes the decriminalisation automatic, allows users as well as addicts to have drugs, setting out the maximum amounts.

While police could still detain people for public consumption or possession of drugs, it appears that those caught would only be recommended to a treatment programme or included on a register of addicts.

Last week, Jerry Sanders, the Mayor of San Diego, California, a short drive from the Mexico border town of Tijuana, said he was "appalled" by the legislation.

"I certainly think we are going to see more drugs available in the United States," Mr Sanders said. "We need to register every protest the American government can muster."

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