The London conference is expected to back efforts to win over Taliban foot soldiers with money and jobs, and review a UN terrorism blacklist to encourage fighters to change sides.
This, combined with a fresh commitment to development and the influx of an extra 30,000 US troops, is meant to break a stalemate in a war now into its ninth year.
"We will see at the end of this year the light on the horizon," NATO military chief Admiral Giampaolo Di Paola said after a NATO meeting in Brussels on Wednesday.
Western governments are hoping a final military and civilian push will put them into a position of strength to begin drawing down troops in 2011 and to negotiate a political settlement.
With public opinion wearying of war, attention is already turning to an eventual exit strategy involving a political settlement with the Taliban leadership - although officials stress that this is not yet on the cards.
"We are not going to negotiate with the Taliban now, and if there's going to be any movement on this issue, the Taliban will have to sever all contact with al Qaeda and this is a critical point," US special envoy Richard Holbrooke said.
Pentagon press secretary Geoff Morrell said that any reconciliation with Taliban leader Mullah Mohammad Omar was "probably a bridge too far" after he gave safe haven to al Qaeda to launch the 9/11 attacks on the United States.
"He has the blood of thousands of Americans on his hands," he told reporters in Washington.
But with the United States also stressing it will be up to the Afghans to decide how to reconcile their country's warring factions, many argue that the question of involving Mullah Omar is more a matter of timing than principle.
"No plan will work without him," said retired Brigadier Sultan Amir Tarar, a former senior member of Pakistan's Inter Services Intelligence (ISI) agency.
"He's respected by Afghans for resisting foreign occupation. How can he be sidelined or dumped at a time when Taliban are winning the war?" he told Reuters.
War weary
Afghan President Hamid Karzai is expected to seek support in London both for a plan to win over foot soldiers - something that has had little success in the past - and to hold a Loya Jirga, a council of elders to discuss broader reconciliation.
The Taliban have so far shown no willingness in public to enter peace talks, though some analysts argue they too are tired of the fighting, and realise they are no better placed than the Americans to win power by military means alone.
The Taliban, in comments posted on one of their websites on Wednesday, renewed a demand that foreign troops leave Afghanistan and dismissed plans to win over individual fighters as a trick.
But they also repeated a statement made by Mullah Omar late last year that they posed no threat to the West - a possible signal of a greater willingness to break with al Qaeda.
Britain is also hoping to use the conference to convince regional players to cooperate rather than compete over Afghanistan, the battleground for proxy wars for 30 years.
Among those attending are the foreign ministers of India and Pakistan, which have long competed for influence in Afghanistan.
(EurActiv with Reuters.)
