The UN want $4.7bn to help the victims of war, famine and natural disaster in 26 countries.
The UN’s emergency relief co-ordinator, Jan Egeland, said that amount was the equivalent of 48-hours of global military spending.
The UN Secretary-General, Kofi Annan, said the international community had the capacity to pay, but now had to display the will to do so.
The UN wants to provide life-saving help to more than 30 million people.
The appeal includes aid for those affected by the earthquake in Kashmir, and the Asian tsunami last December.