The move is made as the region targets top-level drug traffickers instead of street dealers.

The porous lawless border areas of Myanmar, Thailand and Laos have for decades been a hub for heroin production, but the so-called "Golden Triangle" drug trade is now pumping unprecedented quantities of synthetic drugs into the global markets - fuelling a $61 billion drug trade

In large part responsible for the dramatic shift to synthetic drugs is a mega-cartel known as "Sam Gor", which U.N.'s Office on Drugs and Crime (UNODC) believes is Asia's biggest crime syndicate led by a Chinese-born Canadian citizen named Tse Chi Lop.

China is now stepping up efforts with Mekong countries - Myanmar, Thailand, Laos, Cambodia, and Vietnam - to take down Sam Gor in a "joint operation", said an official from China's National Narcotics Control Commission.

"They are one of the major threats," said deputy commissioner Andy Tsang on the sidelines of a Friday meeting to stamp out a regional plan.

"The region as a whole, China included, will do our best to hit it where it hurts the most," he told AFP.

Targeting 'choke points'

The production of methamphetamine -- either in tablet "yaba" form or the highly potent crystallized "ice" version -- ketamine and fentanyl take place primarily in Myanmar's eastern Shan state, but much of the precursor chemicals needed to cook them flows across the border from China.

Law enforcement has long focused on busting low-level dealers and users on the streets, a plan that has proved "static" when faced with the shifting trafficking routes used by Sam Gor, said Jeremy Douglas, UNODC's regional representative for Southeast Asia.

Now drug police from the six countries will share intelligence to target traffickers working at border "choke points" where drugs and precursor chemicals flow are rampant, he said.

"You can't engineer the surge of methamphetamine without the surge of chemicals," Douglas said, adding that besides China, the chemicals also come from Thailand, Vietnam and India.

Sam Gor is also believed to launder its billions in drug money out through businesses springing up along the Mekong - including casinos, hotels and real estate.

Thailand in 2018 netted more than 515 million yaba tablets, 17 times the amount for the entire Mekong region a decade ago - and seizures this year have already outpaced that amount, said the UNODC.

Drug hauls feature in near daily headlines in the region, with police finding pills packed in Chinese tea sachets - though traffickers are finding more creative ways to ship out the illicit products.

On Thursday, Thailand's narcotics police raided a Bangkok warehouse and found 36 kilograms (79 pounds) of ice hidden in the metal frames of treadmills which were about to be shipped to Japan, while another 122 kilograms (25 pounds) were stored in cardboard boxes.