BRUSSELS, Belgium — The European Union will ignore critics who accuse it of helping to boost food prices by embracing a binding target for the use of biofuels, officials said Friday.

The European Commission is sticking to its proposal that biofuels account for at least 10 percent of energy used by the EU's huge transportation sector by 2020, because voluntary targets have failed miserably so far, EU spokesman Michael Mann said.

"If you don't have targets, you don't make progress" in combating climate change, Mann said.

The European Commission has said higher food prices are the result of increased demand for meat and dairy products, particularly in China and India, bad weather in 2006 around the world and speculation in the price of grains and other crops.

At a conference in Brussels on Thursday, aid officials and food policy experts urged Europe and the U.S. to reconsider their biofuel policies.

John Holmes, U.N. undersecretary-general for humanitarian affairs, singled out Somalia, Ethiopia and western African countries such as Guinea as being the worst hit by food shortages and rising prices.

Joachim von Braun, the head of the International Food Policy Research Institute, said Europe and the U.S. must "correct political errors" made when they gave approval to an increased production of biofuels without properly researching the effects on food supplies.

The Brussels-based economic researcher Bruegel said in a report Friday that biofuels do not contribute to energy security, do not achieve cheap cuts in emissions of greenhouse gases and trigger higher food prices worldwide.

In recent weeks, European Parliament members, the international relief group Oxfam, environmental organization Greenpeace and other advocacy groups have all questioned the merit of biofuel targets.

But Mann shrugged off claims that biofuel production triggers higher food costs and said the EU will go ahead with plans to expand the sector.

Mann said there is "good evidence" biofuel production does not boost European food prices "to a significant extent," because no food crops are used for fuel in the EU. "We think that our best contribution can be to make a system that is actually sustainable, that makes us lead by example."

The biofuels target is part of an ambitious climate change package the 27 EU leaders embraced last year.

EU governments are negotiating the details of the package they hope to enact by year's end. The overall aim is for the EU to draw 20 percent of all its energy from renewable sources by 2020 — up from 8.5 percent now.

Mann said the EU had experimented with voluntary targets to no avail. The EU had until now a "voluntary" target of 5.7 percent biofuel use in transportation but "we only arrived at something like 2 percent by 2007. So we were nowhere near it," he said.

Also, the EU does not target such food crops as colza, corn or sugar beets but nonfood sources such as wood chips, straw "and other stuff that is not used for food and would otherwise be thrown away," Mann said. "You have to start on first-generation biofuels to get your productive capacity going, but as soon as possible move on to the biofuels that don't deflect from food production."

Biofuels may reduce dependence on oil, but will actually cost more in the long-run, the Bruegel think tank said.

Also, while sugar cane-based ethanol can reduce emissions by 90 percent compared to petroleum, corn-based ethanol only saves 30 percent of emissions, it said. It argued that when farmers overhaul their fields to grow more biofuel crops, more carbon is produced.