NATO chiefs are in disagreement over the alliance's future in Afghanistan, including plans for it to take overall command of security operations from the US-led coalition there.
British Defence Secretary John Reid
Four days ahead of key Afghan parliamentary elections, US Defence Secretary Donald Rumsfeld spoke of possible future reductions in US troops, and told NATO allies at a meeting in Berlin it was time they helped fight a violent insurgency.
Britain backs Rumsfeld's call for the NATO-led ISAF force to get tougher on the ground. But other European allies, including Germany and France, have resisted a plan that would see ISAF in charge of both peacekeeping and counter-insurgency.
"It isn't something that will happen overnight and without discussion," said British Defence Secretary John Reid.
"People come to this with different primary purposes and different histories...There is a will to get there, but the world is not black and white," he told a news briefing.
NATO currently has some 10,000 peacekeepers in the capital Kabul, the north and the western part of Afghanistan. Assuming elections on Sunday pass off smoothly, it wants to extend its reach into the more dangerous south and east through next year.
But German Defence Minister Peter Struck said ISAF must remain distinct from the U.S.-led Operation Enduring Freedom (OEF) of roughly 20,000 troops which bears the brunt of the fight with Taliban-led insurgents.
"I would not like to expose our soldiers to more danger by linking these two mandates together," he told German radio.
OEF has been fighting in Afghanistan since the 2001 U.S.-led invasion to oust its Taliban former rulers. NATO took charge of the UN-mandated ISAF stabilisation mission two years later.
German Defence Minister Peter Struck
The United States, whose army is badly stretched by the war in Iraq, has dropped an earlier call for NATO to swallow up OEF.
Instead it backs a compromise put forward by NATO Secretary- General Jaap de Hoop Scheffer for a "dual-headed" structure under which the two missions remain separate but report higher up to a single, NATO command.
But France is yet to be convinced.
"These are two missions, they are completely different," French Defence Minister Michele Alliot-Marie told reporters.
"The forces should remain distinct, and their command too," she told a news briefing.
Britain is due to lead NATO's expansion of its peacekeeping duties into the south early next year, a move which could lead to several thousand more NATO troops in Afghanistan.