The European Union and United States need to do more to cut government support for their farmers, members of the Group of 20, led by India and Brazil, and the Cairns group said.

Reforming agricultural trade, an issue that has stalled the World Trade Organization talks, is crucial to moving ahead on a global free trade treaty, they said.

"Meaningful progress this week in Hong Kong on agriculture is crucial to the success of the Doha Round," the members of 20 leading developing nations and the Cairns group, which includes Australia, Canada and New Zealand, said in a statement.

The group reiterated their calls for totally eliminating all forms of export subsidies - government funds paid to domestic producers to promote exports - by no later than 2010.

"Market access continues to hold back progress in other areas," the countries said in a statement. "The dynamics of the negotiations require movements by both the EU and U.S."

Many of the 149 countries participating in WTO talks in Hong Kong this week, meant to conclude trade negotiations launched in 2001 in Doha, Qatar, have accused the EU of blocking progress by refusing to make bigger cuts in its farm tariffs and subsidies.

But the talks have also been stymied by a disagreement over an offer to allow free access to imports from the WTO's 32 least developed nations. Debate over such development-related issues have diverted attention from the core issue of agriculture, the statement said.

"Agriculture is at the center of this round and of the development dividends we seek from it," it said. "Removing distortions and restrictions in international agricultural trade is essential to unlocking the development benefits of trade reform."