BANGKOK — The number of methamphetamine tablets seized in East and Southeast Asia exceeded a billion last year for the first time, highlighting the scale of illegal drug production and trafficking in the region and the challenges of fighting it, the U.N. said Monday.

The 1.008 billion tablets — which would weigh about 91 tons altogether — were part of a region-wide haul of almost 172 tons of methamphetamine in all forms, and was seven times higher than the amount seized 10 years earlier, the U.N. Office on Drugs and Crime said in a report.

“The region is literally swimming in methamphetamine,” said Jeremy Douglas, Southeast Asia regional representative for the U.N. agency, at a news conference in the Thai capital. “There’s going to have to be a radical policy shift by East Asia to address this problem or it’s just going to continue to grow.”

The drugs are largely consumed in Southeast Asia but are also exported to New Zealand and Australia, Hong Kong, Korea and Japan in East Asia, and increasingly to South Asia.