China praised Myanmar's efforts to fight drugs on Wednesday, lauding the actions of a military government often criticised in the United States and Europe for not doing enough to tackle the problem.

Yang Fengrui, head of the Ministry of Public Security's Narcotics Control Bureau, said the amount of drugs entering China from the Golden Triangle, which includes Laos and Thailand, had fallen.

In 2004, China seized 10.8 tonnes of heroin from northern Myanmar, but that had dropped to just 4.6 tonnes last year, leading to a resulting rise in the drug's street price due to its growing scarcity, Yang told a news conference in Beijing.

That area under cultivation has dropped from a high of 165,300 hectares (about 390,000 acres) to 18,600 hectares (45,961), Yang said.

Last September, Washington said that the former Burma had "failed demonstrably" to fight illegal drugs and that it had been "very lacklustre" in interdiction and fighting corruption.

The country was also Asia's largest source of methamphetamine pills, production of which was being ramped up as opium cultivation fell, the report added.

The United States and Europe have been fierce critics of Myanmar's human rights record and continued detention of Nobel Peace Prize winner and opposition leader Aung San Suu Kyi, leading to wide-ranging sanctions.

But China has been a steady friend of the generals who have ruled for decades, standing by them after they crushed a pro-democracy uprising in 1988 and swept aside a 1990 election won by Aung San Suu Kyi and her National League for Democracy.

Yang said the sanctions on Myanmar, toughened following last autumn's bloody suppression of renewed pro-democracy protests, would not affect China's cooperation with Myanmar.

"We will keep cooperating on intelligence exchanges, fighting drug traffickers, eradicating drugs, personnel training and helping the Myanmar government with substitution programmes."

Over the past few years, China has spent around 700 million yuan (51.8 million pounds) on crop substitution programmes in Myanmar to get people to stop farming opium poppies, Yang said.