BEIJING -- China has promised to step up cooperation with the United States in attempting to stem the increasing flow of heroin from Southeast Asia's "Golden Triangle" to America through southern China, according to an assistant U.S. secretary of state.
Melvyn Levitsky, in charge of international narcotics matters for the state department, said that talks last week with Chinese anti-narcotics officials resulted in "strong pledges" from them to exchange more information with U.S. drug enforcement agents.
The promises represent a retreat, at least rhetorically, from public threats by Chinese officials earlier this month to limit cooperation with the United States until a complicated problem involving a Chinese witness in a U.S. drug trial is resolved.
U.S. diplomats here have said that Chinese police officials, while helpful with international narcotics control efforts, often have not been fully forthcoming with needed, detailed information about suspected drug traffickers.
Sino-American cooperation on narcotics matters has become an increasingly important issue with the shift of drug trade routes over the last four years out of the Southeast Asian "Golden Triangle" of Thailand, Laos and Myanmar (formerly Burma).
Since the 1989 takeover of Myanmar by a military junta, heroin production there has doubled, Mr. Levitsky said, with more than half the crop ending up in America, particularly New York City.
And an increasing percentage of that production now begins its eventual movement to the United States through the southern Chinese province of Yunnan, which shares 1,200 miles of largely unpoliced border with Myanmar. Formerly routes through Thailand were mainly used.
The shift in the drug transit routes not only caught Chinese officials by surprise, it also has led to a growing internal drug problem in China for the first time since the Communist regime virtually wiped out drug use in the early 1950s. As a result of the rising drug use, at least 400 cases of the virus linked to Acquired Immune Deficiency Syndrome have been found here as well.
Chinese officials now admit having an estimated 70,000 addicts in their country, most of them in the Yunnan Province.
But the drug problem has spread quickly to major Chinese cities, and a Chinese newspaper devoted to public security issues last week said there were more than 100,000 addicts in a relatively small area of Yunnan bordering Myanmar.
Mr. Levitsky said he also expressed concern to Chinese narcotics officers that there may be some official involvement in the movement of drugs through China.
Chinese officials routinely deny this, although such corruption takes place in all other nations with drug problems.
But a U.S. Drug Enforcement Administration official, accompanying Mr. Levitsky, said there is firm evidence that Chinese suppliers are providing Myanmar drug labs with "a significant amount" of the industrial chemicals needed to refine heroin.
While China earlier this month declared a "people's war" on its drug problems, Chinese drug enforcement officials at the same time said that they were not inclined to cooperate with U.S. agents until a Chinese witness in a U.S. drug trial is returned to China.
The witness -- in a 1988 case that was the first resulting from cooperation between Chinese and U.S. drug agents -- claimed political asylum when he was brought to California to testify.
The witness' asylum request, which Mr. Levitsky said the U.S. government is formally opposing, has set in motion a separate and lengthy legal process that has prevented his return to China -- where frustrated Chinese narcotics agents are waiting to put him in jail.