Afghanistan's cultivation of opium poppy has risen by 10 percent in 2016, according to a new report released by the United Nations.

According to the key findings of its annual Afghanistan opium survey, the UN Office on Drugs and Crime (UNODC) said the total area of land devoted to poppy cultivation had risen 10 percent in 2016 to 201,000 hectares.

The jump in cultivation is due to the favorable weather, the government’s loosening grip on security, and a drop in international support for counternarcotics operation, the UN report said.

"The survey shows a worrying reversal in efforts to combat the persistent problem of illicit drugs and their impact on development, health and security," UNODC Executive Director Yury Fedotov said in a statement.

"Eradication has dropped precipitously to 355 hectares -- a fall of some 91 percent," Fedotov said.

The report also said cultivation was also spreading to new areas, as the number of poppy-free provinces fell to 13 from 14 out of a total of 34.

"It is very disturbing to see a considerable increase in poppy cultivation in the north, which may be linked with a deteriorating security situation in the region," said Andrey Avetisyan, head of UNODC in Afghanistan.

The UN also said there has been a 30 percent increase in the estimated yield from poppy cultivation.

Poppy farmers in Afghanistan are often taxed by the Taliban, which uses the money to fund their insurgency against the government and NATO forces.

General Mohammad Ahmadi, deputy interior minister for the counternarcotics police, said his forces had conducted 1,263 operations this year, in which they arrested 1,408 opium traffickers including government employees and foreigners, confiscated just over 238 tons of opium, and destroyed at least 35 labs across the country.

Billions of dollars have been spent on counternarcotics efforts in Afghanistan in the past decade, including programs encouraging farmers to switch to other cash crops like wheat, fruit, and saffron. But many of those efforts have failed.

Afghanistan’s cultivation of opium poppy is the world’s main source of heroin.

With reporting by AFP and Reuters