The assistance came after Yousuf Raza Gilani, the prime minister, warned that, unless help was urgently given, peace could not be achieved in the region.
Gilani said that the Taliban could exploit discontentment amid a lack of help for people forced to move from conflict zones in the northwest.
"There is an urgent need for a joint and comprehensive response to this issue by all those who are committed to fighting terrorism," he said.
The United Nations said fighting between the army and Taliban had forced about 1.5 million people to flee their homes since May 2, in addition to 550,000 people already displaced by previous violence.
Al Jazeera's Mike Hanna, reporting from Swabi district near the capital, Islamabad, said many had moved in with "friends, family and complete strangers".
He said Pakistanis felt an obligation to help those who have fled, and that their willingness to help was also a sign of public support for the army.
"Those in the area who are lucky enough to have homes help those who are fleeing out of humanitarian compassion, but also as part of a bolstering of popular support, as part of a duty for all Pakistanis who support their government in the struggle to retain a sense of national sovereignty.
"The efforts of the army continue to be supported. If those who are suffering away from their homes turn against the war, it is very damaging to Pakistan."
Dominique Frankefort, an emergency co-ordinator with the UN World Food Programme (WFP), said two million people would need food until at least September.
"There are very few non-governmental organisations and there is very little government assistance," he told the news agency AFP.
"We are catching up, if you have 200,000 additional IDPs [internally displaced persons] coming in per day you cannot feed them immediately."
The Pakistani military is fighting the Taliban in Buner, the Swat valley and Malakand, and says it will expand its offensive to Waziristan to the south.
A military statement on Wednesday said the army had captured the town of Sultanwas, a Taliban stronghold in Buner district, and killed 80 Taliban fighters.
Al Jazeera's Kamal Hyder, reporting from Islamabad, said: "The military has been claiming that it has taken back many towns in Buner.
"[The town of] Daggar they say is now under control of military forces. That has prompted some people to go back. But the vast number of people who fled Buner are still holding back, [fearing] there could be another round of escalation."
The army said it had killed more than 1,057 Taliban in the near four-week-long military offensive, and that more than 60 soldiers had been killed.