"Our assessment is that the current level will continue for the next few years ... in fact rise in 2008, 2009 and probably at least until 2010," she said.

Food prices were rising due to a combination of soaring oil and energy prices, the effects of climate change, growing demand from countries such as India and China and use of crops to produce biofuels, Sheeran told a news conference.

Speculative investment in commodities markets in products such as grains and cereals, which has helped fuel the price surge, is not a short-term phenomenon, she said.

"This is not a short-term bubble and will definitely continue," Sheeran said.

The EU last year set itself a target for biofuels to account for 10 percent of fuel used by transport in the bloc by 2020.

But critics have recently questioned whether the plan needs to be reviewed in the light of concerns about the impact of biofuels on food supplies and whether they really contribute to reducing greenhouse gas emissions.

"Governments need to look more carefully at the link between the acceleration in biofuels and food supply and give more thought to it (biofuels policy)," Sheeran said.

She also said the United Nations needed an extra $500 million from Western governments to meet a food aid gap this year.