Under pressure from the United States, Mexican President Vicente Fox has backed off from signing legislation to decriminalize illegal drug use.
Fox has sent it back to Congress for changes rather than signing it into law as his office had said he would just a day ago. His office now says the proposed law will be tightened "to prevent drug tourism."
The measure would have lifted penalties for possession of small amounts of drugs for personal use, including marijuana and cocaine.
There have been concerns that the measure could increase drug use by border visitors and U-S students who flock to Mexico on vacation.
One supporter of the bill in the Mexican Senate says the bill may be revised to exempt only drug addicts from prosecution.