In a commentary in the International Herald Tribune, Kerry, who heads the Senate Foreign Relations Committee, said that the international community was not meeting its responsibilities toward Pakistan.

"The danger of the floods extends beyond a very real humanitarian crisis," Kerry wrote in Monday's edition.

"A stable and secure Pakistan, based on democracy and the rule of law, is in all of our interests. Pakistan has made enormous strides in combating extremism and terrorism -- at great sacrifice. But its ability to keep up the fight requires an effective response to this crisis."

Pakistanis have grown increasingly angry over the sluggish government response, and are turning to Islamic charities, some of them tied to militant groups.

"We don't want politicians. We want the Islamic groups in power. The government just steals," said Haidar Ali, a college student in the devastated Swat Valley, whose life has been reduced to laying bricks all day in stifling heat.

The floods began in late July after torrential monsoon downpours over the upper Indus basin in the northwest.

In Jampur, in southern Punjab, about 500 km southwest of Islamabad, waters have begun to recede but thousands of people still live in relief camps.

"In about two weeks' time, when the river returns to normal, that's when we expect movement in the population (to go home)," Brig. Zahid Usman said.

The village of Kot Bodla, outside Jampur, has been cut off for a month, and is still accessible only by boat.

"The cotton crop was almost ready," said Abdul Ghafar, a farmer. "It just needed another three weeks, but the water destroyed it."

He added that he did not believe they would be able to sow their winter wheat crop now, which both supplies the village's food needs and gives them something to sell.