Islamabad:
In its latest offensive, Taliban militants have set at least 55 NATO tankers on fire in north-west Pakistan.
The incidents are the latest in a string of attacks since Pakistan closed a key border crossing with Afghanistan almost a week ago.
Islamabad shut down the Torkham crossing along the fabled Khyber Pass last Thursday after a NATO helicopter attack in the border area killed three Pakistani soldiers.
The closure has left hundreds of trucks stranded alongside the country's highways and bottle necked traffic heading to the one route into Afghanistan from the south that has remained open - the Chaman crossing in south-western Pakistan.
"We've seen closures before, and the gate was always reopened in three or four days. It's been a little bit longer now, and we understand very much the political sensitivities here, but we feel it is in Pakistan's interest as much as in our interest to address this. First, because we want to stop militants from crossing the border. Second, because these backed up convoys are becoming a security problem for Pakistan, as militants torch them and threaten the drivers or kill the drivers - and the drivers themselves depend on the money they get from transporting these supplies, so it's not doing anybody any good," said NATO spokesman James Appathurai.
Meanwhile, US envoy to Pakistan, Anne Patterson, has said her country offered its deepest apology to Pakistan and the families of the Frontier Scouts who were killed and injured in the strike. NATO's Gen David Petraeus also vowed to work to stop similar incidents happening in the future.
After sending a report to the Congress in which it was very critical of Pakistan's role in the war on terrorism, the Obama Administration also changed track and publicly praised Islamabad's role in uprooting Al-Qaida and the Taliban.
"We have seen a shift in the Pakistani thinking. Pakistan's support for extremist elements in the past is fairly well understood, but we believe that Pakistan has changed its view and recognises that extremist elements within its borders now represent an existential threat to Pakistan itself and to the civilian government in Pakistan," State Department spokesman P J Crowley told reporters.
"We're seeing, obviously, in the string of attacks of the NATO convoys in Pakistan that the insurgents haven't given up, and we want to see the government continue to take effective action," he added.
This is being seen as a desperate bid to make Pakistan reopen the crucial road link to Afghanistan for its forces.