The British commander in Afghanistan said yesterday that he could use an extra 4,000 troops to fight the Taleban in Helmand province.

Brigadier Mark Carleton-Smith, head of the Helmand Task Force, told Sky News that there were more than enough tasks in the province for another brigade of between 3,000 and 4,000 troops. There are currently 8,000 British troops in southern Afghanistan.

Last week Des Browne, the Defence Secretary, said he had no plans to send more troops to Afghanistan, and insisted that British commanders had not asked for additional units. The Americans are planning to send three more brigades next year, some of whose soldiers could go to Helmand.

In a separate move, Nato's top commander disclosed yesterday that he wanted the troops in Afghanistan to play an expanded role in targeting drugs traffickers.

General John Craddock, Nato's Supreme Allied Commander Europe, said during a visit to Afghanistan that there was no question of alliance troops serving with the International Security Assistance Force (Isaf) being ordered to attack the poppy farmers or to engage in wholesale eradication programmes. He was seeking approval, however, for an interim measure thatwould enable Isaf troops to focus more resources on destroying drug laboratories and detaining the traffickers.

The involvement of Nato troops in counter-narcotics operations has always been highly sensitive because of the perceived fear that any obvious targeting of the poppy farmers would turn the Afghan people against Isaf. A large proportion of the opium industry is in Helmand province where British troops are based. General Craddock said that he was seeking expanded authority from Nato's North Atlantic Council to attack drug trafficking facilities in Afghanistan, where opium is converted into heroin.

He said 1kg of opium was worth about $100 but 1kg of heroin was valued at $3,500.

If Isaf forces could destroy the processing facilities or interdict the traffickers, the general said, the drugs barons would be seriously hit and the Taleban insurgents who rely on income from the trade to buy arms would be affected. Corrupt officials also benefited from the huge profits, he said.

General Craddock dismissed the fear that an increased counter-narcotics role for Isaf troops would provoke the traffickers and the Taleban to attack Nato forces even more ferociously. “This is a totally specious argument. What's more ferocious than IEDs [improvised explosive devices] and suicide bombs?” he asked. “If we do this, we shall cut the legs out from under them because they won't have the money to pay the bomb-makers and buy materials to attack us,” he said.

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