President Barack Obama said for the first time he wants US troops out of major combat in Afghanistan by the end of 2014, the date he and other Nato leaders set for moving Afghans into the lead role in fighting the Taliban.
Allies had different interpretations of that target's meaning. capping a two-day summit of 28 Nato leaders in this Atlantic port city, Mr Obama said that after a series of public disputes with Afghan President Hamid Karzai, and despite the likelihood of more to come, the US and its Nato partners have aligned their aims for stabilizing the country with Mr Karzai's eagerness to assume full control.
"My goal is to make sure that by 2014 we have transitioned, Afghans are in the lead and it is a goal to make sure that we are not still engaged in combat operations of the sort we're involved in now," Mr Obama told a closing news conference.
For some US allies, 2014 is more than a goal when it comes to shifting their troops from a combat role.
"There will not be British troops in large numbers and they won't be in a combat role" by 2015, British Prime Minister David Cameron said. But he added, however, Britain has no intention of abandoning Afghanistan any time soon.
"We may be helping to train their army, we may still be delivering a lot of aid, in effect, because we don't want this country to go back to being a lawless space where the terrorists can have bases," Mr Cameron told Sky news television.
Canada is ending its combat role in 2011.
If Mr Obama's expectation about ending the US combat mission in 2014 holds, it would mark a turning point in a war now in its 10th year, a conflict that once appeared headed for success but that drifted into stalemate during George W Bush's second term in the White House.
Mr Obama entered office in 2009 pledging to end the Iraq war, which he opposed from the outset, in order to shift forces, resources and attention to Afghanistan, a fight he says the US cannot afford to lose.
It remains far from sure, however, that even an expanding and improving Afghan army will prevail without US combat support.
As the US experience in Iraq showed, insurgencies can prove more resilient than predicted and newly assembled government security forces can take longer than expected to become competent and experienced enough to stand on their own.
At their annual gathering, Nato leaders also proclaimed "a true fresh start" in relations with Russia. They agreed to construct a missile defense over Europe, signed a long-term partnership accord with Afghanistan and expressed hope that the US Senate would act quickly to ratify a nuclear arms reduction treaty with Russia that some republicans oppose.