KABUL -- President Hamid Karzai urged Afghanistan's vast diaspora on Thursday to return and lead investment, saying foreign business would not be attracted if Afghans themselves were seen to be wary.

Karzai, speaking at the opening of a four-day seminar on trade and investment, said he was aware that some returnees were finding it hard to establish businesses because of corruption and bureaucracy, but he promised the government would make it easier, Reuters reported.

"In the first six months, we had been too busy with some other important issues that we could not provide them with legal support and rid the traders of bribery and red tape," he said. "In reality, we were not aware as to what was going on in our offices."

After 23 years of occupation and conflict, Afghanistan's economy is in tatters and there is virtually no manufacturing or production of any kind -- apart from agriculture.

Millions of Afghans have fled the country as refugees -- including the bulk of the country's middle and upper classes who ran businesses, factories and industries in better times.

Although international donors have pledged hundreds of millions of dollars in development aid, grants and loans to rebuild the country, the government is keen to encourage direct private investment.

It sees the return of the Afghan disaspora as the catalyst for economic growth.

"There is no country which has got wealthy from foreign donations...we can be wealthy only through our own country's investments," he said. "We ask all Afghans who are currently investing in other countries to come and invest inside the country, which is of national and personal benefit."

The seminar, organized by the Afghan Civil Society Forum and the Swiss non-governmental organization Swisspeace, aims to examine all aspects of investment and business in the country -- from legal issues to banking regulations, labor matters to trade.

Karzai opened and will close the meeting himself, and has ordered all his cabinet heavyweights to make presentations.

But the main aim of the seminar is to get businessmen themselves to decide what they think would best encourage private investment and to present a wishlist to the government today.

Chief among concerns for Afghan and foreign investors alike remains security, with few willing to risk capital while there is still conflict.