SAN DIEGO, Oct 2 The US government today showed its best results in the war against drugs

SAN DIEGO, Oct 2 (Reuters) The US government today showed its best results in the war against drugs in 20 years, but said it has yet to prove it can significantly reduce cocaine and other narcotics distribution over the long term.

White House 'drug czar' John Walters told a news conference widespread reports of cocaine shortages in 37 US cities, leading to a 24 per cent jump in its street price, represent an important milestone for the anti-drug effort.

''But the real challenge is: can we sustain it?,'' said Walters, director of the National Drug Control Policy.

The statistics were announced before the United States launches what is likely to be a substantial aid plan to combat drug distribution in Mexico and along the border, where 90 per cent of the cocaine to the United States enters.

Mexican President Felipe Calderon and US President George W Bush are hammering out details of the plan, which US officials said could be worth $1 billion initially and grow over time. Walters gave no details but said the two leaders could announce a deal soon.

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