THE head of Britain's armed forces has accused NATO allies of "failing to resource" the military mission in Afghanistan, as Prime Minister Gordon Brown agreed to send as many as 1000 more troops to the country.

The criticism by Air Chief Marshal Sir Jock Stirrup and Mr Brown's decision to increase Britain's commitment came as a rift grew among NATO leaders over European members' refusal to send more troops to Afghanistan.

At this weekend's NATO summit in Strasbourg, Mr Brown and US President Barack Obama tried again to persuade France, Germany and other European allies to put more troops on the front line to fight the Taliban.

But European governments refused to deploy more combat troops, and offered only police officers to train the Afghan security forces.

At a joint press conference in Strasbourg with Mr Obama, French President Nicolas Sarkozy ducked the call for more soldiers. "We totally endorse and support America's new strategy in Afghanistan," he said. "We are prepared to do more in terms of police training. We are helping Afghanistan rebuild."

Sir Jock said that, while the strategy for tackling the Taliban was right, NATO had failed to provide enough troops or equipment. "The problem is that we have failed to resource the strategy accurately," he said.

Britain had resisted calls to increase its numbers in Afghanistan, and hoped to pressure the Europeans to do more. But as he arrived in Strasbourg, Mr Brown offered a short-term boost in British troop numbers to 8300, which officials said was conditional on other nations "sharing the burden".