Rich nations came under fresh attack for refusing to give ground on farm protection at world trade talks.
John Powell, deputy executive director, World Food Programme
"Market access continues to hold back progress in other areas, as the EU has yet to table an offer in line with the requirements of the Doha mandate," said the powerful G20 and Cairns Group in a joint statement.
The groups - which account for 27 nations and include Australia, Brazil, China and India - said it was time for the "major agricultural subsidisers and protectionists" to return to the core issues of the Doha or Hong Kong would be "a lost opportunity".
One of the biggest sticking points is the 25-nation EU's refusal to offer lower tariffs on imports of farm goods from developing countries without concessions from them on access to their markets for industrial goods and services.
A top UN food aid official also criticised Europe and the United States for arguing at the Hong Kong trade meeting over whether humanitarian aid should be in kind or in cash.
"What is disgraceful and outrageous is that 18,000 children die of hunger every day, every one of them a preventable death. That's what the controversy should be about," John Powell, deputy executive director of the World Food Programme, told reporters. "We need more food and more cash."
As day four of the World Trade Organization (WTO) talks got under way, more than 100 South Korean farmers gathered in a Hong Kong island park, singing and chanting ahead of big marches later in the day to the US and Korean consulates.
So far, however, there has been no repeat of the rampant violence that marred a 2003 WTO meeting in Cancun, Mexico, where talks on a deal to reform world trade and lift millions out of poverty almost collapsed.
The Hong Kong meeting was initially billed as the last hurdle of the so-called Doha trade round freeing up business in farm and industrial goods and services. But the bar was lowered because of bitter differences between rich and poor nations, though the 150 WTO member states still hope to reach a deal by the end of 2006.