Higher food prices risk wiping out progress towards reducing poverty and, if allowed to escalate, could hurt global growth and security, UN Secretary-General Ban Ki-moon says.

Opening a UN trade and development conference in Ghana, Ban pledged to use the full force of the world body he heads to tackle the price rises, which threaten to increase hunger and poverty and have sparked food riots in Asia and Africa.

"I will immediately establish a high-powered task force comprised of eminent experts and leading authorities to address this issue," he said on Sunday.

The UN head warned the UN Conference on Trade and Development (UNCTAD) meeting huge increases in prices of food staples such as cereals since last year could erase progress made towards UN-set goals of halving world poverty by 2015.

"The problem of global food prices could mean seven lost years ... for the Millennium Development Goals," he said.

"We risk being set back to square one," Ban said.

He noted that several countries had moved to try to offset the food squeeze by barring exports of rice and wheat, or introducing incentives for easier imports of foodstuffs.

"This threatens to distort international trade and exacerbate shortages," he said.

"If not handled properly, this crisis could result in a cascade of others ... and become a multidimensional problem affecting economic growth, social progress and even political security around the world," Ban told the conference.

UNCTAD is meeting in Ghana in West Africa, one of the world's poorest regions whose people are feeling the squeeze of the soaring food prices caused by factors including poor harvests, record fuel prices and tight international supplies.

A series of West African countries, from Mauritania to Cameroon, have been hit by food riots in recent months.

World Bank president Robert Zoellick has warned that surging food prices could push at least 100 million people in low-income countries into poverty.

UN chief Ban called on the countries of the world to successfully wrap up negotiations for a global trade pact aimed at boosting the world economy.

Known as the Doha Round, the negotiations first launched in 2001 have often stalled and missed several deadlines but momentum in the talks has built up in the last two months.

"More trade, not less, will get us out of the hole we are in," Ban said.

"Let us agree the benefits of globalisation can and should be shared more equitably," he added.

Also speaking at the opening of the April 20-25 UNCTAD conference, World Trade Organisation director-general Pascal Lamy said a breakthrough in the Doha Round talks was "doable in the next weeks".