The call came at the beginning of a three-day summit at the U.N. Food and Agriculture Organization's headquarters in Rome, organized to deal with growing hunger and civil unrest sparked by soaring food prices.
The World Bank estimates that about 850 million people are already hungry, and still-climbing food prices threaten some 100 million more, according to Reuters.
"Nothing is more degrading than hunger, especially when it is man-made," Ban told the summit. "It breeds anger, social disintegration, ill health and economic decline. In the name of the development goals we all set at the millennium ... I urge all of you to act together now."
Ban and others called for more agricultural foreign aid, reducing trade restrictions on food, and supplying small farmers with microcredit loans, seeds and fertilizer.
"Some countries have taken action by limiting exports or by imposing price controls," Ban said. "They only distort markets and force prices higher."
Some countries pledged to answer Ban's request. Japanese Prime Minister Yasuo Fukuda promised to release at least 300,000 tons of imported rice from storage, according to Reuters.
One point of contention at the summit will be the impact of biofuel production on climbing food prices. Rising oil prices, extreme weather and agricultural resources diverted to produce biofuel have all contributed to rising food prices.
But the large biofuel-producing countries -- the U.S. and Brazil -- say that biofuel production has contributed a relatively small amount to the recent crisis. The head of the U.S. delegation, Agriculture Secretary Ed Schafer, said biofuels will contribute only 2 to 3 percent of a predicted 43 percent rise in prices this year, according to the Associated Press.
But international organizations, such as the International Monetary Fund, said that biofuel production contributes 15 to 30 percent of the food price hike.
"Food stocks are at their lowest in 25 years, so the market is very vulnerable to any policy changes [promoting biofuels]" Frederic Mousseau, a policy advisor at the food aid group Oxfam, told AP.
Egypt's President Hosni Mubarak asked the summit to create "an international code of conduct" on biofuel production.
Meanwhile, some participants provoked protest merely by attending. Among the 44 heads of state at the conference was President Robert Mugabe of Zimbabwe, who has presided over three decades of declining food production in that country, which was once called Africa's "breadbasket."
"I regard the attendance of Robert Mugabe at this summit as, quite frankly, obscene," Britain's international development secretary, Douglas Alexander, told reporters, according to CNN. "This is a man who has impoverished his country."
Iran's president Mahmoud Ahmadinejad is also attending the conference.
According to the AP, Agriculture Secretary Schafer told reporters in Rome that Ahmadinejad and Mugabe were welcome to attend the summit, but that U.S. delegates would not meet with them there.