A man passes a truck that slipped off a flooded road in Pakistan's Muzaffargarh district of Punjab province Sunday. (Asim Tanveer/Reuters)

The federal government will match, dollar for dollar, money raised by Canadians for relief operations in flood-ravaged Pakistan for the next few weeks, government House leader John Baird said Sunday.

The money will go to the newly established Pakistan Floods Relief Fund and equal contributions made to Canadian registered charities between Aug. 2 and Sept. 12, Baird said.

"We have not placed a dollar limit on the amount of funds that we will provide through this important program," he said.

The latest aid pledge is in addition to $33 million Ottawa promised earlier.

Donors from around the world have so far given or pledged more than $800 million US to help Pakistan cope with the massive floods, Pakistani Foreign Minister Shah Mahmood Qureshi said.

Pakistan is grateful for the international assistance, which came after the United Nations appealed for $460 million in aid for the deluged country, Qureshi said.

"The total commitments and pledges that Pakistan has got so far are $815.58 million," he told reporters in Islamabad. "In these circumstances, when the West and Europe and America are going through a recession …this kind of solidarity for Pakistan, I think, is very encouraging."

The floods began in late July in the northwest after exceptionally heavy monsoon rains, expanding rivers that have since swamped eastern Punjab province and Sindh province in the south.

The deluge has affected about one-fifth of Pakistan's territory. At least six million people have been made homeless and 20 million are affected overall.

About 200,000 in the southern part of the country have fled to higher ground since Saturday to escape new flooding.

Mike Bailey of the World Vision aid agency said four million people in the Swat Valley to the north are cut off from the rest of Pakistan because floodwaters have washed away bridges.

With files from The Associated Press