"It is false we are anti-biotechnology or anti-developing countries," said EU spokesman Gerassimos Thomas. "These things said by the United States are simply not true."
On Monday, Mr. Bush criticized European restrictions on bio-engineered food, saying they were based on unfounded, unscientific health fears.
"Because of these artificial obstacles, many African nations avoid investing in biotechnology, worried that their products will be shut out of important European markets," Mr. Bush told a meeting of the Biotechnology Industry Association in Washington.
"For the sake of a continent threatened by famine, I urge the European governments to end their opposition to biotechnology," he added.
U.S. farmers estimate EU biotech restrictions have cost them nearly $300 million a year in lost corn exports alone. The issue has soured the world's biggest trading relationship and will loom large at an EU-U.S. summit Wednesday in Washington.
Thomas claimed the EU spends seven times more on development aid to Africa than the United States. He said the EU focuses its spending on longer term improvements to help African farmers improve their yields.
U.S. officials have previously blamed the EU restrictions for decisions by African nations to reject American food aid because it contains genetically modified grain.
European Union authorities imposed a moratorium on the import of genetically modified food products in 1998, responding to mounting fears of European consumers about possible health risks from the products.
Talks between the two sides broke off last week at the World Trade Organization in Geneva and the United States said it would seek a WTO ruling to end the EU moratorium on grounds that it is an unfair trade barrier.
Genetically modified crops are engineered by scientists to be heartier, yield more food or require less water or pesticide.
Proponents say genetically modified foods offer developing countries a chance to make their farms more productive, which will not only feed their people but also allow their economies to diversify away from subsistence farming, increase education levels and reduce poverty.
The Department of Agriculture convened a meeting this week of 100 farm ministers to discuss the promise of GM food.
Protesters outside the talks spoke not of promise, but peril.
Opponents say not enough is known about the safety of the food, or the effect of the "GM" plants on the environment. At least one GM food company does not allow farmers to save seeds from one crop to plant the next year's, a traditional practice. Some GM crops could spread to fields where non-GM crops are grown.
Other critics say the problem for African farmers is the lack of access to Western markets, thanks to barriers like the EU's Common Agricultural Policy and U.S. farm subsidies.
With world commodity prices falling, it's possible the problem isn't the size of the food supply but how it is distributed, some observers note.