We expect Saudi Arabia, much as it helped Afghanistan in other times, to help the Afghan people rebuild their country

Afghan Foreign Minister Abdullah Abdullah

He has now left for Tokyo for a high-profile international donors' conference on Afghanistan, that will be co-chaired by Saudi Arabia.

An Afghan spokesman told the BBC Pashto Service that Crown Prince Abdullah had promised $20m immediately, with further assistance to be announced at the Tokyo conference.

Saudi officials have not confirmed the amount, although the official Saudi Press Agency reported that King Fahd expressed Saudi Arabia's "constant support for the Afghan people".

Saudi Arabia was one of few countries that recognised the Taleban regime which was ousted by the US-led military campaign last year.

Mr Karzai began his visit on Friday by performing an Umra, or lesser pilgrimage, at the Islamic Holy Places in Mecca and attended a royal banquet given in his honour in the capital Riyadh on Saturday.

Aid sought

Afghan Foreign Minister, Abdullah Abdullah, said Afghanistan was counting on the oil-rich Gulf state's support.

"We expect Saudi Arabia, much as it helped Afghanistan in other times, to help the Afghan people rebuild their country," he said.

Saudi Arabia will play a major role at the Tokyo conference as a co-chairman

"I think relations will be expanded in all aspects."

One immediate result of the visit is tipped to be the reopening of the Saudi embassy in Kabul.

Saudi Arabia froze ties with the Taleban in 1998 to protest against the presence in Afghanistan of the Saudi-born dissident, Osama bin Laden, and severed completely after the 11 September suicide attacks in the US, which Washington blamed on Bin Laden.

Afghanistan is looking for up to $30bn in international aid over the next 10 years for assistance in a variety of sectors, from health and education to removing mines.

After attending the donors' conference in Tokyo on 21-22 January, Mr Karzai is due to visit China.