Rising prices for opium in Southeast Asia and the global economic downturn may trigger a surge in the cultivation of the illegal drug in Myanmar, which until recently was in sharp decline, U.N. drug experts said Monday.

Nearly all the world's opium comes from Afghanistan but military-ruled Myanmar is the second biggest source, accounting for almost 5 percent of global production.

In 1999, the country set out to become opium-free by 2014 and the campaign made considerable strides, with the amount of land cultivated for opium plummeting from 322,000 acres (130,300 hectares) in 1998 to 53,000 acres (21,500 hectares) in 2006.

A United Nations report released Monday however said that the amount of land being cultivated climbed to 70,400 acres (28,500 hectares) last year, mainly due to rising prices.

"Rising opium prices may make it more attractive for farmers to revert back to opium cultivation, especially if no alternative sources of income are available," Antonio Maria Costa, executive director of the United Nations Office of Drugs and Crime, said in the report, which called for more international assistance.

The strong increase in the price of Myanmar's opium was due to reduced production and continued demand from China, Australia and other countries in the region, it said.

Weak prices for legal agricultural commodities make the situation more difficult, as does the soft global economy, said an experts at a news conference to release the report.

"We would expect that with the global financial meltdown many people will be unemployed," said Gary Lewis, also from the U.N. agency. Most will try to earn their living legally, "but when those options are exhausted they will turn quite naturally to other means to survive. Some of those will involve trafficking in illicit and narcotic products."

Myanmar in 2008 is estimated to have produced 410 tons of opium, involving the work of 840,000 people and $123 million in revenue for those farming the poppy plant, it said.

Prices being fetched for Myanmar's opium contrast sharply with falling prices for the crop in Afghanistan, where most of the world's opium comes from and where several years of overproduction has created a glut.

The average price paid to farmers in Myanmar for the 2008 opium harvest was $137 per pound ($301 per kilogram), up from the 2007 average of $120 per pound ($265 per kilogram). In Afghanistan, the average price in November 2008 was $55 per kilogram, down sharply from early 2007 when it was above $100 per kilogram.

Dramatic differences in the price of opium between regions and sometimes even within regions or countries is not unusual, the report said.

The region of Southeast Asia where the borders of Myanmar, Thailand and Laos meet, known as the Golden Triangle, produced more than half of the world's opium in 1990 and one-third in 1998.