The U.N. mission is still reeling from the pre-dawn assault on a guesthouse in the capital that left five U.N. staffers dead. Though the U.N. insists it remains committed to Afghanistan, its actions show how much security has degraded in the country and raise questions about the future of its work if attacks continue.

The relocations follow a U.N. decision on Monday to suspend much of its work in the volatile northwest of neighboring Pakistan because of increasingly targeted attacks.

In Afghanistan, some 600 nonessential staffers will be moved for three to four weeks to more secure locations in and outside of Afghanistan while the body works to find safer permanent housing, spokesman Aleem Siddique said.

The majority of the U.N.'s 1,100 international staff in Afghanistan live in the capital, spread out in more than 90 guesthouses.

The plan is to consolidate those living arrangements so staff can be better protected, Siddique said. He stressed this was not a pullout or a scale-down in operations. About 80 percent of the U.N.'s staff in Afghanistan are Afghan citizens.

"We've been here for over half a century and we're not about to go any time soon," Siddique said. Still, much U.N. work in Afghanistan has been put on hold since the attack and employees have been given the option to take leave while officials consider how to better protect employees.

In the Oct. 28 attack, gunmen wearing suicide vests stormed a private guesthouse where dozens of U.N. staffers lived, killing five U.N. workers and three Afghans. The Taliban claimed responsibility for the assault, saying they intentionally targeted U.N. employees working on the recent presidential election.

Secretary-General Ban Ki-moon has requested an additional $75 million to help with security improvements and crisis preparation in Afghanistan after the attack, spokesman Adrian Edwards said.

"There is no going back to the previous situation we were in. Our security clearly isn't up to the job of dealing with these kinds of attacks," Edwards said.

In Pakistan, the U.N. has suspended long-term development work projects with a five-year or longer time frame - in the tribal areas and the North West Frontier Province - regions that border Afghanistan and have large areas under Taliban control.