By Catherine Davis BBC correspondent in Kabul

He said the needs of Afghanistan were much greater than those estimated at a donor conference in Tokyo in 2002, when $4.5bn was pledged over a five-year period.

Little has been done to rebuild the Afghan economy

President Karzai was speaking in Kabul at the start of a two-day meeting of the Afghanistan Development Fund attended by senior government officials and international donors.

He expressed gratitude for the assistance already given but he also made it abundantly clear that a lot more was needed - as much as $15-20bn according to his government's estimate.

Mr Karzai said that before the Soviet invasion in 1978, Afghanistan had been self-sufficient in agriculture.

It had foreign exchange reserves and had been one of the world's largest exporters of raisins.

"Our desire," he said, "is to reach at least that stage first, but it will take many years and international assistance."

Weariness

This was not just a one-sided plea for help, though.

The president pointed to the reforms the country had already undertaken and said Afghanistan was well aware that it had to work hard to create its own resources.

His words were echoed by the finance minister, who stressed the importance of sustainability.

There is a sense here that, even in the capital, ordinary Afghans are growing tired of all the talk of reconstruction.

They want to see improvement - roads rebuilt, jobs, proper hospitals, not only the white jeeps of international agencies.

Security however remains a fundamental issue.