By Alastair Leithead
BBC News, Kabul
Nato forces in Afghanistan have been criticised for paid adverts on a radio station implying it is acceptable for farmers to grow opium poppies.
Poppy production is an important income source for many farmers
The crop, which is the raw material of heroin, is expected to be grown at record levels again this year.
Criticism over the adverts came from both the UN and the Afghan government.
The UN last month said that although production of opium poppies had fallen in the north and centre, a sharp rise was likely in the lawless south.
The controversial announcement, paid for by Nato forces, appeared on a local radio station in Helmand province.
Nato says it has no responsibility for poppy eradication
It told farmers growing opium poppies that their fields would not be destroyed by Nato or the Afghan National Army.
It appeared to imply that it was alright to grow the illegal crop.
The advertisement said troops from the International Security Assistance Force (Isaf) understood that most Afghan people had no other source of income and troops are there not to eradicate opium poppies but to bring security and kill foreign militants.
The majority of heroin in Europe comes from Afghanistan and reducing opium poppy production is a major priority for the Afghan government and the international community.
But the military has distanced itself from eradication efforts as angry farmers who have lost their livelihoods would be more likely to join the Taleban insurgency.
The UN Office on Drugs and Crime representative in Kabul, Christina Oguz, said that such a policy was sending mixed messages to farmers
"Isn't it a kind of a dubious message? There is this very strong link between insurgents and drug traffickers," she said.
"I'm afraid that the farmers can be confused at that and believe that everybody's leading the drugs side which is not a good message."
The Afghan government said it had not been aware of the advertisement, but Nato had apologised for putting it on a local radio station.
But an Isaf spokesman said it was not a new policy, as the force is in Afghanistan to provide security.
He said that issues relating to poppies are the responsibility of the Afghan government.