Officials declined to give details of the three days of closed-door meetings, held at a Geneva hotel and not at the U.N.'s European headquarters, saying they were part of contingency planning for a conflict they hoped could still be avoided.
"We still hope there will be no war in Iraq. It is the responsibility of all responsible organisations to prepare for any eventuality," World Health Organisation spokeswoman Fadela Chaib told journalists.
U.N. sources said Cyprus emerged as the likely coordinating centre for relief operations at the meeting, organised by the U.N. Office for the Coordination of Humanitarian Affairs (OCHA).
It was attended by U.N. relief agencies including the U.N. refugee agency UNHCR and the WHO. The Swiss-run International Committee of the Red Cross (ICRC) sent observers.
The United Nations appealed in December for $37.4 million to set up stocks of food and other supplies in case of war.
U.N. contingency plans circulated at the time said that 4.5 to 9.5 million of Iraq's 22 million people could quickly need food to survive once a military campaign began. Some 900,000 might flee to neighbouring countries, while 500,000 casualties could need treatment, according to the document.
Kris Janowski of the U.N. High Commissioner for Refugees (UNHCR), said: "We are not trying to put a veil of secrecy on all this but we simply don't know what is going to happen.
"The preparations are really based to a large extent on guesswork," he added. "We don't have good scenarios. All we have is past experience, the 1991 Gulf War which of course is not going to repeat itself."
The UNHCR led relief efforts for two million refugees in the Gulf War, mainly Iraqi Kurds in the north where Western powers now enforce a "no-fly" zone.
It has an emergency stockpile of materials -- plastic sheeting, jerrycans, blankets -- in Denmark which it can fly anywhere in the world at short notice.
"It is very general stockpiling...which is used whenever you have population movements. But then we don't even know whether there will be any population movements, let alone in which direction," Janowski said.
The ICRC has also been stockpiling goods in and around Iraq.
ICRC operations director Pierre Kraehenbuehl said last month that up to 100,000 people could be displaced each month during an Iraq conflict.
- Reuters - Thomson Reuters Foundation
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