The announcement comes as Islamabad struggles to provide help to hundreds of thousands of people who have fled their homes in the northeast of the country, where government forces are battling Taliban fighters.
Lieutenant-General Nadeem Ahmed, who leads a group dealing with those displaced by the conflict, said that the country needs donations of fans and high energy biscuits.
Mike Hanna, Al Jazeera's correspondent in Islamabad, said that most of those who have fled the fighting are staying with family and friends.
"This is obviously placing an immense amount of strain on the resources of the society as a whole, increasing the magnitude of what is the biggest movement of people since the formation of Pakistan in 1947," he said.
John Holmes, the UN humanitarian chief, said only about 20 per cent of displaced civilians are inside about 24 refugee camps at the moment.
Ron Redmond, a spokesman for the UN refugee agency, said the displacement of so people in such a short space of time "could go back to Rwanda" - a reference to the two million people displaced by the 1994 massacre of ethnic Tutsis by the majority Hutus in the African country.
The United Nations estimates that about 1.4 million people have been displaced since fighting in Pakistan's Northwest Frontier Province (NWFP) started at the end of April.
That estimate is in addition to about 550,000 people already displaced by fighting across the NWFP and in other Pakistani regions.
"The situation is volatile and changing rapidly," Holmes said at the UN headquarters in New York.
Redmond said a lack of help for the displaced and the many thousands of families hosting them could cause more "political destabilisation" for the country.
The US has praised Pakistan's military operation in the NWFP, which comes amid pressure from Washington to root out al-Qaeda and Taliban hide-outs along the country's border with Afghanistan.