More than 60 UN workers were withdrawn from the country in August after three staff members were killed.

The agreement, which focused on security guarantees for returning workers, was signed after five days of talks in the Pakistani capital, Islamabad.

A UN spokesman said the actual return of staff would depend on what it called "satisfactory reports" from the Taleban on investigations into the killings.

Danger for aid workers

Concern about security reached a peak after an Italian UN military observer was gunned down following the United cruise missile attack on suspected terrorist bases in eastern Afghanistan on August 20.

Two Afghan workers were also killed in July in the eastern city of Jalalabad.

The UN has in the past complained to the Taleban about harassment of women aid workers, and the closing down of their offices in Kabul.

But the Taleban have said they are now very keen for the UN workers to return, primarily to continue their humanitarian aid operations.

Human rights off agenda

Discussions about human rights were not part of the brief of the latest talks despite being a major issue of concern among the international community.

A UN official said dialogue on such issues would continue with the Taleban, but within Afghanistan.

The latest talks between the two sides began while the UN's special envoy to Afghanistan, Lakhdar Brahimi, was still in Islamabad as part of his mission to ease tensions between the Taleban and Iran. He succeeded, at least for the time being, in defusing the military stand-off along the frontier.

Mr Brahimi is now visiting neighbouring central Asian states in his attempt to bring peace to Afghanistan - a task which he acknowledges is a difficult one.

In Tajikistan, he has met the veteran Afghan opposition commander, Ahmad Shah Massoud.