The worst floods in Pakistan's history have hit at least 14 million people, officials say.
Twelve million are affected in Khyber Pakhtunkhwa and Punjab provinces, while a further two million are affected in Sindh.
In Indian-administered Kashmir, at least 113 people died in mudslides.
Meanwhile, it has emerged that a charity connected to a group with alleged al-Qaeda links has been providing flood relief.
Flooding has submerged whole villages in the past week, killing at least 1,600 people, according to the UN.
And the worst floods to hit the region in 80 years could get worse, as it is only midway through monsoon season.
According to the federal flood commission, 1.4m acres (557,000 hectares) of crop land has been flooded across the country and more than 10,000 cows have perished.
A UN official, Manuel Bessler, told the BBC that with crops swept away by floodwaters, some Pakistanis could be forced to rely on food aid to get through the winter.
He said the immediate priorities for survivors were clean drinking water and medical assistance.
Anger is growing at the absence of President Asif Ali Zardari, who left the country to visit Britain for talks with Prime Minister David Cameron.
With flood victims bitterly accusing the authorities of failing to come to their aid, the disaster has piled yet more pressure on an administration struggling to contain Taliban violence and an economic crisis.
Gen Nadeem Ahmed, of the National Disaster Management Authority (NDMA), said 12 million people had been affected in Khyber Pakhtunkhwa and Punjab provinces, where 650,000 houses were destroyed.
The cost of rebuilding roads there was put at some 5bn Pakistani rupees ($59m, £38m), while the bill for fixing damage to power infrastructure and dams would come to another 2.5bn rupees.
"In my opinion, when assessments are complete, this will be the biggest disaster in the history of Pakistan," the general said in Islamabad.
Along a 1,200km (750-mile) stretch of the River Indus in Sindh province, the government has evacuated one million people and is evacuating another half a million, provincial minister for irrigation Jam Saifullah Dharejo told the BBC.
About half a million people from the area left their homes earlier to stay with family and friends.
"The flood is at its peak right now, and we expect the waters following to start to recede once these torrents have passed," the minister said.
Pakistan's meteorological department has predicted further downpours for the country, especially in flood-affected areas.
In Kashmir's Ladakh region, mudslides swept through the town of Leh early on Friday, killing at least 113 people and injuring 400, local official T Angchok told the BBC.
The two main roads into the town were closed as was the airport, and medicines, blankets and tents were in short supply.
In Khyber Pakhtunkhwa, a charity with links to a group blamed for the Mumbai attacks has been providing flood relief, one of its leaders told the BBC.
Falah-e-Insaniat has close links to Jamat ud Dawa, an organisation linked in turn to Lashkar-e-Taiba, which was banned by Pakistan after the 2008 attacks on the Indian city.
The head of Falah-e-Insaniat in Risalpur, Adil Mir, said his volunteers had helped thousands of people.
Jamat ud Dawa came to prominence through its relief work during the 2005 earthquake in Pakistani-administered Kashmir.
The BBC's Adam Mynott says the concern is that while the Pakistan government is being widely condemned for failing flood victims, Falah-e-Insaniat has responded quickly and is recruiting supporters right across the country.