A vendor displays bananas for sale along a road in the Port area of Manila in this file picture

The World Trade Organisation's marathon-running chief has urged his staff to eat bananas to sustain themselves through long negotiating sessions -- in which tariffs on the fruit are among the most contentious issues.

Pascal Lamy asked the WTO's roster of economists and lawyers to work "enthusiastically" and with "team spirit" during a high-stakes meeting of trade ministers that began on Monday.

"We will be asked to work long hours, to do work on all sorts of potentially unexpected assignments that may crop up, but such is our fate!" the normally staid Frenchman wrote in an e-mail to staff.

"What do I recommend during your long work hours in the next two weeks? Bread and bananas, or any other high energy diet at your disposal!" he said in the e-mail sent out last week.

About 30 trade ministers and 800 government officials are in Geneva seeking a long-sought deal on cuts to import tariffs and subsidies that skew trade in goods from cotton to cars.

Among the hot-button issues being discussed are the European Union's import duties on bananas which are higher on Latin American imports than those from other former European colonies.

Ecuador, Panama, Costa Rica, Colombia and Peru want those rules overhauled before accepting a new global trade pact which requires consensus among the WTO's 153 members to be clinched.

Bananas for sale in the WTO cafeteria during the talks carry Chiquita stickers from Costa Rica.