Nato worried about Pak-Afghan border

But, speaking at the opening of a new intelligence-gathering centre for the North Atlantic Treaty Organisation, General James Jones declined to criticize the Pakistani government over its management of border security.

"It's clear that the border is not a sealed border," he said, when asked if Pakistan's behaviour was leading indirectly to the deaths of Nato soldiers in Afghanistan.

But he said: "I quite understand the concerns of our troops on the ground... and we are going to be working on this problem assiduously in the weeks and months ahead."

Nato assumed command of foreign forces throughout Afghanistan this month, taking charge of the east of the country from the US-led coalition that toppled the Taliban regime five years ago.

The Taliban insurgency has worsened dramatically in recent months, with insurgents killing scores of foreign and Afghan troops in mass attacks and also intensifying a vicious campaign of suicide and roadside bombings.