Pakistan's armed forces rescued a further 2,000 people stranded by rising floodwaters, they said on Friday, while the country's best-known charity warned that only a small fraction of millions affected by the floods had been reached so far.

Record monsoon rains and melting glaciers in northern mountains brought floods that have killed at least 1,208 people, including 416 children, the National Disaster Management Authority (NDMA) has said.

Pakistan is struggling to respond to the floods given their unprecedented magnitude. The government has said 33 million people - 15% of its population - have been affected.

The United Nations has appealed for $160 million in aid to help tackle what it said was an "unprecedented climate catastrophe" as Pakistan's navy has fanned out inland to carry out relief operations in areas that resemble a sea.