UNITED NATIONS -LRB- CNN -RRB- -- The United Nations is calling on NATO to do more to stop the Afghan opium trade after a new survey showed how the drug dominates Afghanistan 's economy . Afghan villagers tend to opium poppies in Taliban-controlled Helmand province in April 2007 . The report from the U.N. 's Office on Drugs and Crime shows the export value of this year 's poppy harvest stood at around $ 4 billion , a 29 per cent increase over 2006 . Despite Afghan security forces ' efforts to curb the trade , 660 tons of heroin and morphine were trafficked out of the country in 2007 , the report said . Opium is derived from poppies , and the data on cultivation was collected by examining satellite images and by assessments on the ground . The report said opium has accounted for more than half of Afghanistan 's gross domestic product in 2007 . InvestorWords.com defines GDP as the total market value of all final goods and services produced within a country in a given period of time , usually a calendar year . According to the U.N. survey , about a quarter of the earnings from opium go to farmers . The rest goes to district officials who collect taxes on the crop , to drug traffickers and to the insurgents and warlords who control the trade . Antonio Maria Costa , executive director of the U.N. Office on Drugs and Crime , urged NATO to take a more active role in countering the spread of the drug trade , which has increased dramatically since the American-led invasion to remove the hard-line Islamist government of the Taliban in October 2001 . `` Since drugs are funding the insurgency , NATO has a self-interest in supporting Afghan forces in destroying drug labs , markets and convoys , '' Costa said in a written statement to coincide with the release of the survey . `` Destroy the drug trade and you cut off the Taliban 's main funding source . '' James Appathurai , a NATO spokesman , said coalition forces were equally concerned by the rapid growth in the narcotics trade . `` We share the U.N. 's concerns , '' Appathurai told CNN . `` Drugs not only poison people , but they poison economies and governments , and it is in everyone 's interest to stop this proliferation . '' He said NATO forces were providing assistance to Afghan police through training and transport but he said there were no plans to deploy coalition troops to intervene directly . `` The issue of whether we can do more is certainly a live discussion for NATO , but at the moment this is a matter for the Afghan government , '' Appathurai said . Farming of opium poppies has been almost eradicated in the north and west of the country , Appathurai said . However , he said , in the lawless southern provinces and especially in the Taliban stronghold of Helmand , poppy production was going on largely unchecked . According to the report , U.N. observers have noticed a proliferation of heroin labs in neighboring countries and along trafficking routes . Costa said the labs are dependent on precursor chemicals , like acetic anhydride , that must be smuggled into the region . He called for tighter controls in chemical-producing countries and stronger intelligence-sharing between Afghanistan and its neighbors . `` Drug trafficking is a transnational threat , and therefore national initiatives have their limitations , '' the U.N. drug chief said . Appathurai said the most effective way to curb the drug trade was tackling the insurgency head-on . He also said it was important to provide alternative work for poor Afghan farmers to encourage them to give up opium production . `` You can not have eradication in isolation . If we do n't give them the support to produce alternative crops , then by wiping out their opium fields , you are only creating enemies for the future , '' he said . E-mail to a friend