United Nations aid agencies have provided assistance to hundreds of thousands of victims of Pakistan's worst floods in decades but relief operations have yet to reach an estimated six million people.
The lives of 14 million people - eight percent of the population - have been disrupted by one of the worst catastrophes in Pakistan's history. Six million still need food, shelter and water, the UN said in a statement.
Highlighting the scale of the disaster, Prime Minister Raza Yusuf Gilani said in an Independence Day speech the country faces challenges similar to those during the 1947 partition of the subcontinent.
Thousands of families were torn apart after the bloody partition into Hindu-dominated India and Muslim-majority Pakistan that led to the flight of at least 10 million refugees in the greatest migration in recorded human history.
The floods, triggered by torrential monsoon downpours just over two weeks ago, engulfed Pakistan's Indus river basin, killing up to 1,600 people.
Pakistan's government, overwhelmed by the disaster, has been accused of being to slow to respond to the crisis with victims relying mostly on the military and foreign aid agencies for help.
Anger is spreading, raising the possibility of social unrest. In Sindh province, flood victims complain of looting and there are signs of increasing lawlessness.
"The government has given us half a carpet. We have received rice and medicine from the government but no tent," said 22-year-old labourer Zarsheed.
Analysts say a military coup is unlikely because the army's priority is fighting Taliban insurgents, and seizing power during a disaster would make no sense.
The military has said it won't interfere in politics. It already sets security policies and heavily influences foreign policy, and is described by some as a state within a state.
UN Secretary-General Ban Ki-moon is expected to visit Pakistan over the weekend to discuss the crisis.
Floods have affected about one-third of Pakistan, an area the size of a European country, says the UN Among other urgent problems, clean drinking water is needed for an initial target of six million people.
The floods roared down from the northwest to Punjab province to Sindh, where more flooding is expected. Sindh is home to Pakistan's biggest city and commercial hub Karachi. Floods have damaged mostly rural areas there, although concerns are rising that other urban centres are at risk.
Scattered thundershowers with few heavy falls are expected in the upper northwest, upper Punjab, parts of the north and Kashmir over the next 24 hours, said the Meteorological Department.
Scores of villages have been wiped away. Some people only have a patch of land to stand on. Fresh downpours could bring more destruction, and displacement.
In the town of Muzaffagarh in Punjab, 500 fuel trucks line both sides of a highway. Like about two million Pakistanis, the drivers live in the open, sleeping on mats under their vehicles.
"There may be fuel shortages in southern Punjab though fuel supply is normal in the rest of the country," Yusuf Shahwani, president of All Pakistan Oil Tankers Association, told Reuters.
Along the same stretch of road, about 5,000 people live in and around the median along a 10 km (6 mile) stretch. Relief groups stop and hand out lentils. Motorists throw water bottles out car windows at children who run alongside vehicles.
The economic costs of the flooding are staggering, making it tougher for the government to carry out strategic spending in former Taliban bastions to win public support.
Wheat, cotton and sugar crops have all suffered damage in a country where agriculture is a mainstay of the economy.
World Bank President Robert Zoellick said the floods may have destroyed about $1 billion worth of crops and that the Bank was considering reprogramming about $900 million in aid.
The International Monetary Fund has warned of major economic harm and the Finance Ministry said it would miss this year's 4.5 per cent gross domestic product growth target.
In his speech Gilani called on Pakistanis to rise to the occasion and face challenges posed by the floods.
"The nation faced the situation successfully at that time (of the partition) and Insha Allah (God willing) we will emerge successful in this test," he said.
The UN is increasingly worried about water-borne diseases. A cholera case has been confirmed at a hospital in the northwest Swat valley and suspected cases are being examined. Aid agencies are taking proactive measures to head off a potential crisis.
UN humanitarian operations spokesman Maurizio Guiliano said at least 36,000 people believed to have potentially fatal acute watery diarrhoea are being treated for cholera, instead of undergoing tests in order to save time.