Reconciliation with the Taleban is possible, says Gulab Mangal, the governor of Afghanistan's troubled Helmand province.
But he said it was not possible with the extreme members, who had links to international terrorism.
Governor Mangal told the BBC the keys to defeating the Afghan insurgency were reconciliation and better governance.
Also, he said, the elimination of the Taleban's sanctuaries that straddle the Afghan-Pakistan border.
The energetic and reform-minded Governor Mangal is much favoured by Britain, which has over 8,000 troops deployed to Afghanistan.
On a day when news broke of three more British deaths in Helmand province, bringing the total killed since 2001 to 148, he said that coalition soldiers fighting the Taleban were doing it "for the sake of the world's humanity".
In a reference to al-Qaeda-linked insurgents, he said if Helmand province was not secure, then London would not be either.
He denied recent reports that the Taleban were in control of more than half of his province and insisted that Nato and Afghan security forces were jointly inflicting heavy losses on the Taleban and interrupting the narcotics trade, in which he said they were heavily involved.
"We have taken serious steps towards the narcotics problem," he told a news conference earlier.
"Dozens of smugglers have been captured, many heroin facilities have been destroyed and 41 tonnes of drugs have been confiscated.
"The Taleban and drug dealers are working closely together and we have proof that the Taleban are forcing farmers to plant opium poppies and punishing them if they refuse," he said.
"The Taleban are even escorting drugs convoys around the country and out of it for export. But this year [because of our efforts] you will see a decrease in poppy production."
But Governor Mangal did not deny that his government was having to confront serious problems in Helmand, a province which continues to see some of Afghanistan's fiercest fighting.
He divided the Taleban into three categories, only two of which he said could be negotiated with.
The first was those fighters with international links like al-Qaeda, and these the Afghan government would never reconcile with.
The second group, he said, was nationalist jihadis fighting primarily to expel foreign forces from their land, and these he believed could eventually be brought into the government.
The third group listed by Governor Mangal was comprised of those Afghans who had joined the insurgency for personal reasons, such as resentment of weak government or abuse at the hands of the authorities; these too, he believed could be reconciled with.
As to how long the international coalition would need to stay in Afghanistan, Governor Mangal would not be drawn.
But on one point he was clear: the insurgency, he said, could not be defeated unless the Taleban's sanctuaries were eliminated.
He likened this to bailing water out of a boat at sea.
"If there is a hole in the boat and the water is coming in and we are taking it out with a bucket," he said, "we will never be able to stop the sea water coming in if we don't plug the hole."