Bank director general Rajat Nag said the surging cost of food affects one billion poor in Asia who spend a lot of their wages on food.

"I think at this meeting there will be lots of discussion on the food situation," he said ahead of the start of the four-day gathering.

The ADB, which last year handed out just over 10 billion dollars (6.4 billion euros) in loans, has offered to lend money to Asian governments so that they can subsidise the price of food staples for the poor.

In the long term, the ADB is looking to boost investments in agriculture infrastructure projects such as rural roads and irrigation systems that will help increase farm output and make it easier to get goods to market.

On the eve of the meeting, donors pledged 11.3 billion dollars to the bank's Asian Development Fund, its key poverty alleviation mechanism, for the 2009-2012, a 60 percent increase over the last four-year period.

The fund provides grants and low interest loans to Asia's poorest countries to help them build roads, provide clean water and electricity and agriculture infrastructure.

"With child malnutrition still widespread in Asia, and the global food crisis threatening to reverse the gains nations have achieved in reducing poverty, support for rural infrastructure and rural finance is critically important," ADB president Haruhiko Kuroda said in a statement.

Prices for the benchmark Thai variety of rice, a food stable across much of Asia, are at about 1,000 dollars a tonne, up threefold from the last ADB annual meeting in Japan one year ago.

The jump in food prices is fueling inflation globally and the ADB predicted it will hit 5.1 percent across Asia this year, its highest level since the Asian financial crisis a decade ago. This is raising concerns of popular unrest.

The food crisis has been blamed on poor harvests caused by drought, use of agriculture commodities to make biofuels, and surging demand, especially from China and India, as living standards rise.

Some major Asian exporters of rice, such as India and Vietnam, have imposed restrictions on exports of the staple in a bid to secure domestic supplies.

The ADB opposes such measures, saying it amounts to hoarding at the national level and arguing it distorts the market.

The future of the bank is also under discussion at the meeting amid a simmering internal row among members over its long-term strategic plan.

Last month the United States, which with Japan is the ADB's largest shareholder, took the unprecedented recent step of voting against the plan that outlines the bank's policies until 2020 because it wanted a greater focus on the region's poorest members.

The ADB is owned by its 67 member countries -- 48 from the Asia-Pacific region, and 19 from elsewhere around the world, including Spain.

Since it was established in 1966, the lender has grown from helping Asian governments develop infrastructure projects to promoting the role of the private sector in development.

Some 3,000 people -- business and government leaders, academics and representatives of non-governmental organisations -- are taking part in the ADB's annual meeting, which is being held in Spain for the first time.

It holds the annual meeting outside of Asia every two years.