Kabul: Foreigners are fuelling the problem of corruption in Afghanistan, a country ranked as one of the most corrupt in the world, the Afghan President Hamid Karzai said on Sunday.

"We have problems with both Afghans and foreigners... Our foreigner colleagues have not only been uncooperative but sometimes they have created obstacles," he said during a speech in Kabul on corruption.

"One of the ways to curb corruption is that foreigners should stop giving out contracts to the relatives of the high ranking government officials. We have to revise and reform the contract system", Karzai said.

"We have lost our mutual trust: foreigners think we go corrupt for political reasons, and we think they are corrupt for the same reason."

In a global survey published this month by Berlin-based anti-graft watchdog Transparency International, Afghanistan was again named one of the world's most corrupt nations.

Karzai said the problem of corruption was exacerbated by uncertainty over the future of the country.

"We have to work together with our foreigner friends to give people assurance."

Afghanistan pledged at a major conference in Germany last Monday to step up the fight against corruption in return for sustained international support.

"Afghan government institutions at all levels should increase their responsiveness to the civil and economic needs of the Afghan people and deliver key services to them," Afghanistan and its international partners said in a communique after the Bonn meeting.

"In this context, the protection of civilians, strengthening the rule of law and the fight against corruption in all its forms remain key priorities."

Experts say corruption is an endemic problem among many officials in Afghanistan and that the government and foreign powers must do more to combat it.

The US government has spent billions on aid to Afghanistan since 2002, much of which goes through contractors.