Yury Fedotov, head of the UN Office on Drugs and Crime (UNODC), called the findings sobering, Xinhua reported quoting UN spokesperson Martin Nesirky as saying at a daily news briefing.
Fedotov underscored the need for an integrated, comprehensive response to the drug problem, embedded in a long-term security, development and institution-building agenda, he said.
The 2013 Afghanistan Opium Survey, released in Kabul by the Afghan ministry of counter narcotics and UNODC, said the area under cultivation rose to 209,000 hectares from last year's total of 154,000 hectares -- higher than the peak of 193,000 hectares in 2007.
Almost 90 percent of opium poppy cultivation this year remained confined to nine of Afghanistan's 34 provinces, including those most affected by the insurgency, the survey found.
Helmand, the principal poppy-producer since 2004 and responsible for nearly half of all cultivation, expanded the area under cultivation by 34 percent, followed by Kandahar, which saw a 16 percent rise, it added.
In addition, two provinces -- Balkh and Faryab -- lost their "poppy-free" status, leaving 15 provinces poppy-free this year compared with 17 last year, it said.
Farmers may have driven up cultivation by trying to shore up their assets as insurance against an uncertain future resulting from the withdrawal of international troops next year, according to UNODC.