Japanese prime minister Taro Aso pledged 1.5 trillion yen ($US17 billion) in aid to other Asian countries on Saturday.
The announcement was made at the World Economic Forum in Davos.
The BBC reports the money will be spent over three years on infrastructure projects and promoting trade to boost regional growth.
Mr Aso called on wealthy nations to help smaller countries and warned against protectionism.
Asia's banks have weathered the financial crisis better than those in Europe and the United States. But the region's economies have been hit as the global downturn saps demand for consumer goods.
Mr Aso also said that the assistance would be on the precondition "that the flow of trade and investment not be prohibited".
"We will resolutely fight all protectionism," he said.