Rome  - UN Secretary General Ban Ki-moon opened Monday the United Nations food summit in Rome with a stark reminder of the plight affecting the world's hungry, and a warning that the situation will worsen unless harmful climate change is curbed.

"This day, more than 17,000 children will die of hunger. One every five seconds. Six million children a year," Ban said.

He was addressing some 60 heads of state and government attending the three-day gathering which is being hosted by the UN Food and Agriculture Organization (FAO) at its Rome headquarters.

Ban also referred to a symbolic, personal fast he made Sunday ahead of he summit in an effort to draw attention to global hunger.

"It was not easy. But, for too many people, going without food is a daily reality," he said.

Pope Benedict XVI in a keynote speech scheduled later, was expected to urge rich nations to do more to combat hunger which according to the FAO currently affects more than 1-billion people worldwide.

However, some critics, including development activists, are denouncing the absence from the summit of many leaders from the world' richest nations.

US President Barack Obama who is on an Asian tour is not scheduled to attend.

Indeed, the only government leader from the Group of Eight most- industrialized nations present on Monday was Italian Prime Minister Silvio Berlusconi.

A 70-per-cent increase in food production will be required by 2050 when the world's population which is forecast to top 9 billion, Ban told delegates.

He also stressed the connection between food security an climate change ahead of the international environment conference in Copenhagen in December, when world leaders will attempt to forge a new agreement to curb rising global temperature.

"If the glaciers of the Himalaya melt, it will affect the livelihoods and survival of 300 million people in China and up to a billion people throughout Asia," Ban warned.

Africa's small-scale farmers who produce most of the continent's food and depend mostly on rain could see their harvests cut by more than half by 2020 because of climate-change induced drought, Ban said.

The FAO says some 44 billion dollars - or 17 per cent of official development aid - needs to be directed annually towards agriculture and food production, if hunger is to be eradicated in developing countries.

In 2009 agriculture is expected to receive only 5 per cent of development aid, according to FAO Director-General Jacques Diouf who also addressed summit delegates on Monday.

The FAO hopes the summit will also secure urgent aid to some 31 poor countries particularly stricken by the global economic crisis and in a context where food prices remain high despite good world cereal production this year.

Especially hard hit is East Africa, where drought and conflict have left an estimated 20 million people in need of emergency food aid.

The FAO also advocates longer-term strategies that would allow millions of small-scale farmers to earn a livelihood again, including extending irrigation services, fertilizer supplies, and improved transport infrastructure such as roads, to allow agriculture products to reach markets. (dpa)