President Obama has made it clear to key congressional power-brokers that his administration's rethink of US military strategy in Afghanistan will not see a significant reduction of troop numbers and a narrower counter-terrorist focus on al-Qaeda.

Mr Obama met key Republican and Democrat leaders in the White House State Dining Room last night to discuss a request from his top commander on the ground for up to 40,000 extra troops to help defeat the Taleban insurgency.

The meeting, on the eve of the eighth anniversary of the first US air strikes against al-Qaeda targets in Afghanistan, were an attempt to make clear that the decision Mr Obama faces is one that transcends normal party politics.

But the meeting produced a sharp exchange of views between Mr Obama and his former rival for the presidency, the Republican senator John McCain, who effectively accused the President of dithering while US troops remain under fire.

According to people at the meeting, Senator McCain told Mr Obama that he should not move at a "leisurely pace" while US commanders wait for a decision on troop levels. The comment drew a sharp response from the President, who replied that nobody felt more urgency than he did about the war and there would be nothing leisurely about his decision.

During a 90-minute discussion, Mr Obama did not show his hand on possible troop increases. But he did make clear that that the war would not be reduced to a narrowly defined counter-terrorism effort in the border areas with Pakistan, a strategy that has been linked with his Vice-President, Joe Biden.

“Given the importance of the policy to our security – and to our troops – the President said that he will be rigorous and deliberate, while moving forward with a sense of urgency,” one senior Obama administration official said.

“The President reiterated that we need this debate to be honest and dispense with the straw man argument that this is about either 'doubling down' or leaving Afghanistan."

Mr Obama has already added 21,000 troops to the force in Afghanistan so far this year, raising the total to 68,000, and many Democrats are openly opposed to any further increase.

According to both Republican and Democratic aides, Mr Obama may be considering a more modest injection of troops – closer to 10,000 than 40,000 – but the White House insists that no decision has yet been made.

“We do recognise that he has a tough decision, and he wants ample time to make a good decision,” said House Republican leader John Boehner. “Frankly, I support that, but we need to remember that every day that goes by, the troops that we do have there are in greater danger.”

That fact was underlined by new details of a battle on Saturday in which eight American troops were killed, the heaviest loss of life for US forces in a year.

CNN reported that the attack on Forward Operating Base Keating, which is in a valley in Kamdesh District in eastern Afghanistan, involved about 200 insurgents, who had hidden mortars, rockets and heavy machineguns in the mountains around and were able to pin down the Americans from ridge lines.

The attack appeared designed to exploit the fact that the Americans were already moving away from the base under a new strategy to consolidate forces in more populated areas. A military official told CNN that at point US forces had to pull back as the attackers breached the perimeters of the base.

Later today, Mr Obama is due to meet with his "war council", including Mr Biden, the Secretary of State Hillary Clinton and Robert Gates, his Defence Secretary.

The issue of troop numbers is also on the agenda in Britain after a spat yesterday between Downing Street and the former head of the Army, General Sir Richard Dannatt, over the Gordon Brown's rejection of a plea earlier this year for 2,000 more troops to be sent to Helmand province.

Ministers are expected to give the green light this week to a further 500 troops, taking the number to more than 9,500.

As the death toll rises in Helmand, especially from roadside bomb attacks, the Government has been accused of failing to equip UK forces properly, but a poll for the BBC showed that the level of opposition to the war has not risen much over the past three years.

Fifty-six per cent of those surveyed said they were against British military operations in Afghanistan, while 37 per cent supported them, the ICM poll found. The same poll three years ago found 53 per cent opposition and 31 per cent support.

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