Tokyo:  The World Trade Organisation (WTO) should push food-producing countries to maintain exports to prevent a worsening of the international food crisis, the European Union Trade Commissioner Peter Mandelson said on Thursday.

Ballooning food prices have sparked riots in Bangladesh and brought down the government of Haiti, while some countries have banned exports of staple foodstuffs in an attempt to avert domestic shortages.

Prices of rice, a staple in most of Asia, have risen 68 per cent since the start of 2008. US rice futures rose to an all-time high on Tuesday. "If we restrict trade, we're simply going to add food scarcity to the already large problems of food shortages that exist in different countries," Mandelson said in an interview during a visit to Tokyo with an EU delegation.

"The WTO stands for free trade. It needs to exert its pressure and influence to reduce tariffs and thereby encourage trade," he added.

"It's also got to stand up against export restrictions, export taxes, which too will stop the free flow of trade in foodstuffs and agricultural produce."

Mandelson's comments came a day after a concerned Japan, which relies on imports for much of its food, said it would propose the WTO set clear rules on food export restrictions.

Trade bans on rice have been put in place by India, the world's second largest exporter in 2007, and Vietnam, the third biggest, in the hopes of cooling domestic prices of the staple food.

The export curbs have been criticised by the Asian Development Bank, which said Asian governments were over-reacting to surging food prices by resorting to market-distorting measures.

In Thailand, the world's largest rice exporter, farmers have planted a rare third crop and are expected to reap another 1.6 million tonnes of rice paddy this year.

An incomplete 500,000 tonne tender by Manila last week has reinforced a perception in the Thai rice industry that demand is far outstripping supply, suggesting prices are set to continue the unprecedented surge of the last four months, exporters said.

Mandelson said concerns over food and global financial turmoil were spurring progress towards an agreement on the Doha round of WTO negotiations, which aims to forge a deal to liberalise world trade.

The next ministerial meeting on the Doha round may be held in late May or June, after speculation it could be in the week of May 19, Kyodo news agency quoted Mandelson as saying on Tuesday.

European Commission President Jose Manual Barroso and Japanese Prime Minister Yasuo Fukuda also expressed "strong concern" about rising food and fuel prices and agreed on the urgent need to address the issue, especially in developing countries.