Former President George H.W. Bush had to cancel a planned trip to quake-devastated Kashmir on Tuesday because of harsh winter weather that grounded aid flights for a third straight day. Instead, he toured a mammoth tent camp for survivors on the outskirts of the Pakistani capital of Islamabad.

The elder Bush is U.N. Secretary-General Kofi Annan's special envoy for the South Asian quake. His mission is to convey the plight of the victims to donors, and ensure they make good on their pledges.

"My role will be mainly to encourage people who have pledged money, to get it in," Bush said at a joint news conference with Pakistani Prime Minister Shaukat Aziz. "I couldn't go out of town because of the weather, darn it all."

Nevertheless the president's father said he had a good visit.

"I've learned a good deal, and now I'll head back and start working on the mission," he said.

Bush's visit came amid a flare-up of tensions between the U.S. and Pakistan over a U.S. airstrike Friday on the Pakistani village of Damadola in a tribal region bordering Afghanistan.

Pakistani intelligence officials have said Ayman al-Zawahri, Al Qaeda leader Usama bin Laden's top lieutenant, had been invited to a dinner in the village to mark an Islamic holiday but did not show up and sent some aides instead. The provincial government said at least four foreign terrorists were killed in the strike, along with 18 local people.

When asked about the airstrike, Bush responded: "I'm here as a representative of the (U.N.) secretary-general, so I leave that to someone else to comment. The feeling is that the U.S. is trying to help the people of Pakistan, and I hope that is what prevails."

There was no evidence of hostility toward Bush in his tour of the tented camp.

Washington considers Pakistan a critical ally in its war on terror and bin Laden and al-Zawahri are believed to be hiding out somewhere along the border between Afghanistan and Pakistan.

At the same news conference, Aziz said Pakistan "cannot accept any action within our country" like the missile attack but stressed the bilateral relationship with Washington remained important.

Bush toured the camp surrounded by a tight cordon of security. Partly funded by the United States, the camp is now home to 30,000 victims of the Oct. 8 quake, which killed 87,000 people and left millions more homeless — almost all of them in northwestern Pakistan and the Pakistani-controlled part of divided Kashmir.

Confronted with a classroom of camp students slightly bewildered by their surprise visitor, Bush introduced himself saying, "I used to be president."

Bush moved comfortably between mud-encircled tents housing as many as 10 people. He frequently stopped in front of dwellings to ask questions, sometimes cradling young children who popped their heads out during his brief visit.

One survivor, Syed Munawar, took the opportunity to chronicle his woes but also said he intended to rebuild.

"You have a good attitude," said Bush, who left later Tuesday for Qatar.

In the Himalayan territory of Kashmir, snow at higher elevations and heavy rain and fog elsewhere have made flights too treacherous in recent days, U.N. World Food Program spokeswoman Caroline Chaumont said.

The current weather pattern — with freezing temperatures at higher elevations — will persist at least until the weekend, Pakistan's Meteorological Department said Tuesday. An avalanche warning was also issued earlier.

A senior government official in Muzaffarabad, the capital of Pakistan-administered Kashmir, said Tuesday that thousands of people are stranded along at least three key roads blocked by landslides.

It will take about four days to clear the roads after the rains and snow stop, said Mohammed Mushtaq Awan, chief engineer at the highways department in Kashmir. The key Muzaffarabad-Islamabad link is one of the roads that remains blocked, he said.

Despite frequent calls for donations, officials say the U.N. is still far short of the $550 million it needs to keep all its projects running at full capacity.

International aid organizations are pleading for more funding from rich nations and corporations, which they say will help to stave off more deaths that could come from the cold. Many are without adequate shelter, clothing and are heavily reliant on food aid.