A map produced by the BBC suggests only 38% of Pakistan's North West Frontier Province (NWFP) and surrounding areas is under full government control. The map, compiled by the BBC's Urdu language service, was based on local research and correspondent reports as well as conversations with officials. It shows the Taleban strengthening their hold across the north-west. Pakistani President Asif Ali Zardari rejected the findings, telling the BBC it was an "incorrect survey".
He was speaking after talks in London with UK Prime Minister Gordon Brown, who pledged £12m ($18m) in humanitarian aid for north-west Pakistan.
Mr Zardari said the two countries were united in fighting the threat to their countries' democratic way of life, and also repeated assurances that his country's arsenal was in safe hands.
There was an international outcry recently when the militants moved into Buner district, just 100km (67 miles) from Islamabad.
Pakistan has continued its military offensive to regain control of the region, and has reported the deaths of 11 militants in the Swat valley in the past 24 hours.
Residents trapped in Mingora, the main town in Swat, told AFP news agency by telephone that militants had planted mines and were digging trenches.
"People are becoming mentally ill, our senses have shut down, children and woman are crying, please tell the government to pull us out of here," said one shopkeeper, who did not want to give his name.
"Forget the lack of electricity and other problems, the Taleban are everywhere and heavy exchanges of fire are routine at night."