President Karzai has vowed to cut corruption in the government
Afghan forces could take control of security in some provinces by the end of 2010, delegates at a key summit about the country have said.
A statement at the end of the one-day meeting in London said the process could be complete within five years.
UK Foreign Secretary David Miliband said 2010 was a decisive year as a new government was in place and there was a "refreshed counter-insurgency" plan.
World leaders pledged $140m (£87m) to win over low-level Taliban fighters.
Meanwhile, UN sources have told news agencies that the UN representative to Afghanistan, Kai Eide, secretly met Taliban members this month.
They said meeting was held on 8 January in Dubai at the militants' request. Mr Eide denied to the BBC that the meeting took place on 8 January but refused to comment on any other dates.
Afghan President Hamid Karzai recently announced plans to encourage Taliban members to renounce violence and join in peace talks.
"We must reach out to all of our countrymen, especially our disenchanted brothers, who are not part of al-Qaeda, or other terrorist networks, who accept the Afghan constitution," he told delegates.
David Miliband: ''Grievances need to be pursued by politics and not through violence''
Mr Miliband, restating Britain's support of the plan, said the summit participants were also behind it.
"Today alone there have been over $140m worth of commitments for the first year of the national reintegration programme and we are committed to seeing that through."
Mr Miliband said: "The aim of the conference was to align the military and civilian resources of every coalition partner behind a clear political strategy, to help President Karzai and his government deliver the ambitious agenda that he set out in his inaugural speech last November.
"The themes of mutual responsibility - Afghan and international - and of unity behind a clear plan came through very strongly indeed."
The final communique from the summit in London said it welcomed Afghanistan's goal of taking charge of the "majority of operations in the insecure areas of Afghanistan within three years and taking responsibility for physical security within five years".
COMMUNIQUE'S KEY POINTS
Handover security duties in Afghan provinces starting in late 2010 or early 2011
Funds to reintegrate Taliban who cut ties with al-Qaeda
Hold a 2010 summit in Kabul to develop concrete plans for the Afghan government programme
Backs start of discussions on a new Afghan-led IMF programme
Increase share of aid delivered through the Afghan government to 50% in two years
Increase Afghan military strength to 171,600 and police numbers to 134,000 by October 2011
It said the international community would continue to improve the capabilities of the Afghan security forces, boosting the army to 171,600 and the police to 134,000 personnel by October 2011.
The summit said the Afghan government had acknowledged that it had to tackle corruption.
'No exit strategy'
The High Office of Oversight would investigate and sanction corrupt officials, and once conditions for aid delivery were met, the proportion of aid channelled through the government would rise to 50%, Mr Miliband said.
US Secretary of State Hillary Clinton said reforms planned by President Karzai, such as tackling corruption and effectively managing aid, were important and the US would be watching them carefully.
The security transition from international forces to Afghan forces would also enable the US to start withdrawing its troops from the country in mid-2011.
Hillary Clinton: ''We can begin to transition security to the Afghan security forces''
But Mrs Clinton said: "This is not an exit strategy. It is about assisting and partnering with the Afghans."
The summit said the Afghan government had made progress on economic development, and it hoped it would continue to boost agriculture, human resources and infrastructure.
The BBC's diplomatic correspondent Jonathan Marcus said the theme of the conference was unity and coherence, but also an acknowledgement that there was no military solution to Afghanistan's problems.
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