The United Nations is withdrawing some of its international staff from Pakistan for at least six months for security reasons.
UN officials say only non-essential staff will be moved out and operations to aid refugees and people displaced by fighting will not be affected.
Authorities in Pakistan are reported to have asked the UN to reconsider the decision.
In October, a suicide bomber blew himself up in an office of the UN World Food Programme in Islamabad, killing five staff members.
