The United States, Britain and other allies have promised not to abandon the new Kabul government, as President Ashraf Ghani outlined his vision for a more self-reliant Afghanistan at a London conference.

In Thursday's meeting of envoys from more than 60 countries, Ghani said observers who had predicted doom for Afghanistan as the international military presence wound down were wrong.

"History will not be repeated. We have overcome the past," Ghani told diplomats at the end of the conference.

After agreeing to form a national unity government with chief executive officer Abdullah Abdullah in September, Ghani has vowed to build up Afghanistan's self-reliance, reducing its dependence on aid by boosting its feeble economy and rooting out corruption.

"The world is not responsible for everything for Afghanistan. It is us who are responsible for everything," Ghani said. "We are determined to do business differently."

He said he was confident Afghanistan would overcome its challenges.

"We hope that we will never need direct combat support [again], because the last thing we want is more blood,'' he said. "Peace is a top priority for us."

'Moment of transformation'

British Prime Minister David Cameron assured Afghans that "we are with you every step of the way".

Foreign aid to Afghanistan has 'low impact'

US Secretary of State John Kerry also addressed the conference, promising to back Ghani's reforms and hailing a "moment of transformation" for Afghanistan.

"We have a government in Kabul that merits our confidence... They can be confident of the support of the international community," he said.

The 13-year international combat mission in Afghanistan ends December 31, although Ghani has signed security agreements with Washington and NATO permitting a continued international military presence.

About 10,000 American troops will remain by the end of the year.

Thursday's conference served as a follow-up to a 2012 meeting in Tokyo, where allies pledged $16bn to help rebuild and stabilise Afghanistan's government.

But officials in London would not discuss how much of that money Kabul so far has received, even as they acknowledged that, in the short term at least, Afghanistan cannot survive on its domestic revenues alone.

Since 2012, the United States has sent Afghanistan's government $8bn in assistance, and Kerry promised on Thursday to ask the US Congress to approve "extraordinary" but unspecified levels of new aid through 2017.

Source: Agencies