MICHAEL SETTLE and IAN BRUCE.

Gordon Brown insisted yesterday that British forces in Afghanistan were intent on eliminating the Taliban, not negotiating with them.

Forcefully dismissing reports that the UK Government was embarking on a new strategy to talk to the extremists, the Prime Minister pledged a long-term British commitment with £450m in additional aid over three years, maintaining around 7800 troops with extra armoured vehicles and helicopters and training 70,000 more Afghan soldiers next year.

He also made clear that the UK Government would increase its efforts to get more allies involved in "burden-sharing". The issue is on the agenda at a Nato summit in Edinburgh tomorrow.

Welcoming troop commitment from Denmark, France, Holland, Germany and Estonia, Mr Brown said this had to be "matched" by contributions from other Nato members.

"Where countries are unable to deploy their own troops, we are urging them to look at innovative ways to burden share and help fund those countries who can provide troops and equipment," said the Prime Minister.

Robert Gates, the US Defence Secretary, expressed his exasperation yesterday at the lack of some allies' contribution to the cause, saying: "I am not ready to let Nato off the hook. We need about 3500 military and police trainers, 20 helicopters and three infantry battalions. I am constantly frustrated by the inability of our allies to step up to the plate."

He made clear he had vetoed any future moves for the US to plug the gaps in combat units and transport helicopters.

"We have already extended the tour of a brigade of 3500 men of the US 10th Mountain Division in Afghanistan this year and kept a helicopter detachment in Kandahar for an extra six months. I have refused to extend that or any other helicopter deployment beyond January," he said.

Mr Gates called on Nato countries which imposed crippling rules of engagement on the forces they had sent to Afghanistan to relax their approach to possible casualties.

Germany forbids its helicopter pilots to fly after dark while Norwegian special forces are under orders not to take part in any action further than a two-hour flight from the nearest military hospital.

In the Commons Mr Brown, confirming that allied forces had retaken the Taliban stronghold of Musa Qala in Helmand province yesterday morning, told MPs: "We are winning the battle against the insurgency - isolating them and eliminating the leadership of the Taliban, not negotiating with them."

However, he did back the efforts of Hamid Karzai, the Afghan president, to win over former insurgents who were prepared to give up violence and accept the country's democratic constitution.

Senior government sources acknowledged the latest plan, which follows a five-month internal policy review, represented a "shift in emphasis" rather than a fundamental change in direction.

While the top Taliban leadership is thought to comprise around a dozen senior figures, the Afghan government has been concentrating its efforts on persuading middle-level commanders to break away from the insurgency with their followers. So far, 5000 fighters are said to have laid down their arms.

"This is not a question of negotiating with the Taliban, it is a question of splitting the Taliban," said one Whitehall source.

"This is an Afghan-led effort that has been going on for some time, directly co-ordinated by President Karzai," he added.

Mr Brown, who undertook a whistlestop trip to Afghanistan earlier this week, told MPs how British forces would get 150 additional protected patrol vehicles as well as extra Sea King helicopters. There would be a further £450m in development and stabilisation assistance from 2009 to 2012, both for long-term reconstruction work and quick "high impact" projects intended to help secure the loyalty of the local population.

The Afghan army would be expanded from 50,000 to 70,000 troops with the help of 340 British military trainers and mentors as part of the process of enabling the Afghans to take responsibility for their own security.

Government sources acknowledged, however, that they would not be capable of operating autonomously until 2012 and even then would probably need some continued assistance.