Pakistan`s army chief vowed Wednesday to keep NATO`s supply line to Afghanistan open and reaffirmed support for the military alliance`s mission there, a senior NATO officer said.

In a two-hour presentation, General Ashfaq Kayani also urged NATO to engage with Pashtuns living in tribal regions near Afghanistan rather than simply try to seal the border to stop Taliban militants crossing over.

`We will do whatever is possible, whatever is within our power to ensure that this line of supply is open,` Kayani told top officers in Brussels, according to Admiral Giampaolo Di Paola, head of NATO`s military committee.

`We understand how critical it is to Afghanistan ... and because we want Afghanistan to succeed we would harm ourselves if we did not do our best to ensure that,` Di Paola quoted Kayani as saying.

`A stable and peaceful Afghanistan is in the vital interests of Pakistan.`

Pakistan barred delivery of sealed containers and oil tankers through the Khyber Pass -- NATO`s main supply line -- last week after Taliban militants in the rugged lawless area hijacked and looted 15 trucks destined for Afghanistan.

On Monday, movement of fuel tankers and food trucks resumed to the NATO and US-led forces in Afghanistan after paramilitary escorts were added and a new checkpoints set up on the route.

Pakistan`s tribal belt has become a safe haven for hundreds of extremists who fled Afghanistan after the US-led toppling of the hardline Taliban regime in late 2001.

The Pakistani military is currently fighting Taliban and Al-Qaeda-linked militants in the Bajaur tribal district, where officials say more than 1,500 rebels have been killed and hundreds more captured since August.

Di Paola said Kayani also `made a very in-depth and complex presentation` to NATO chiefs of defence explaining why factors of geography, culture and history make it impossible to stop people crossing the border.

`There is no force which alone can block (the border). Flow across that line is part of normal life for centuries, will continue to be part of normal life for centuries,` said Di Paola.

It is only by `engaging the people living there, and having their understanding and their support that we can facilitate a solution,` he said.