Army chief: We cannot beat the Taliban without reinforcements

Troop numbers in Afghanistan must increase to contain the surge in violence, says the commander of British forces in Helmand.

In an interview with The Independent ahead of Gordon Brown's visit to the province yesterday, Brigadier Mark Carleton-Smith said: "We are probably still on a growth trajectory before we get to the stage when the UK presence can begin to thin out." The commander of 16 Air Assault Brigade estimated it would be up to five years before Britain could consider dropping troop numbers.

Senior military officers are reported to have held preliminary talks on increasing British soldiers in Afghanistan from 8,000 to 12,000 – a dramatic difference from the 3,300 initially expected to hold the ground when the UK force took over Helmand in 2006. The boost in numbers ties in with suggestions that troop levels in Iraq be scaled back.

Senior Nato commanders are said to be "screaming out" for more boots on the ground in Afghanistan.

Two thirds of the way through its tour, 16 Air Assault Brigade has experienced the predicted summer surge in violence. The resignation of Pakistan's President Pervez Musharraf has led to fears that Islamist groups in the country will take advantage of the ensuing turmoil to step up attacks in Afghanistan.

Brigadier Carleton-Smith, who has been in charge during a tour which has cost 24 servicemen and one woman their lives, said he expected the British would at least maintain such high force levels for three to five years. "One of the characteristics of counter-insurgency, unlike conventional war, is the more successful you are in the short term, the more troops you require," he said. "The more ground and the more people you become responsible for, the more troops you need.

"I could use more helicopters – any tactical operational commander could. But there is no point in thinking that aviation is going to make a strategic difference."

The Prime Minister, during a fleeting visit to Afghanistan en route to the Olympics in Beijing, met Brigadier Carleton-Smith and the governor of Helmand, Gulab Mangal, before flying to Kabul to hold talks with President Hamid Karzai.

Mr Brown was not drawn on troop levels but likened the soldiers' courage and dedication to the Olympic medallists. "You make our country proud every day of the week and every week of the year," said the Prime Minister. "You are truly the heroes of our country."

At a joint news conference with Mr Karzai, Mr Brown insisted that coalition forces were gaining ground despite a vicious summer offensive.

Brigadier Carleton-Smith said he remained "cautiously optimistic", citing the now symbolic town of Musa Qala and the southern frontline post of Garmsir as two key "centres of gravity" which have been taken from the Taliban. "They [the Taliban fighters] are recognised for what they are – a brutal, criminally orientated terrorist organisation with no interest in the Afghan population," he said. "The local population is overwhelmingly hostile to the Taliban. The Taliban is quite tactically resilient but it is not joined up at the strategic level."

He said the key to British withdrawal from Helmand was a strong local army, police and government. In one year, the number of Afghan National Army forces in Helmand has increased from 2,500 to 4,300 and while Nato troops remain the leading force, they are increasingly working alongside local soldiers. The Afghan army has 70,000 troops with plans to build the force up to 122,000 – but it lacks armour, air power and medical support.

Brigadier Carleton-Smith concluded: "Armies have never controlled Afghanistan. There has always been a political settlement."