Nato head Jaap de Hoop Scheffer has said he believes there is no military solution to the Afghan situation.
Mr Schaffer wants Pakistani support for Nato troops in Afghanistan
Mr Scheffer was speaking during talks in Pakistan on ways of containing the Taleban insurgency on the Pakistan-Afghan border.
Violence in Afghanistan has returned to levels not seen since the Taleban were ousted in 2001.
More than 4,000 people were killed last year in fighting between militants and international-led forces.
"It is my strong opinion that the final answer in Afghanistan will not be a military one and cannot be a military one," the Nato secretary general told a joint news conference after talks with President Pervez Musharraf in Islamabad.
"The final answer in Afghanistan is called reconstruction, development and nation-building."
Nato troops are facing renewed levels of Afghan violence
Pakistan's Foreign Minister, Khurshid Kasuri, said his country had deployed more troops and suffered more casualties than international forces in its attempts to secure the border.
"The onus for border control cannot be placed on Pakistan alone," he told the news conference.
"We expect a matching response from Afghanistan as each side must play its due role to combat the menace of terrorism."
Pakistan has suggested fencing and mining parts of the border to stop militants crossing.
However, the Afghan government opposes this on the grounds that it will divide families within the Pashtun tribal belt.
It and Western military commanders have accused Pakistan of allowing pro-Taleban militants to operate in its border tribal regions.
Mr Scheffer's visit is seen as part of a wider effort to ensure Pakistan's support in the conflict in Afghanistan against the Taleban and the wider "war on terror".