Refugee leaders said they need at least two years to move out of the camps bordering Afghanistan's restive Kunar province which have provided shelter for more than 20 years to Afghans fleeing their war-torn homeland.
"We have set up businesses and purchased property during our stay since the early 1980s," refugee leader Sher Muhammad said.
"To wind up the businesses and sell our properties we need at least two years to stay," he said, calling on the government to review its decision.
Pakistan's government has ordered camps in the Bajaur and Kurram regions of its semi-autonomous tribal area in North Western Frontier Province to close by 31 August because of "security concerns".
The authorities had earlier taken similar action in the tribal North and South Waziristan regions where Pakistani security forces have been trying to drive out suspected al-Qaida and Taliban fugitives.
Scene of clashes
Kunar province was the scene of recent clashes in which US-led troops suffered considerable casualties last month.
The government gave the refugees the option of returning to their home country or relocating away from the Afghan border.
Pakistan has hosted Afghan
refugees for over 20 years
Refugee leaders meeting in Bajaur's main town of Khar expressed surprise at the order as Pakistan has hosted them for more than 20 years.
More than 105,000 Afghan refugees live in camps in Bajaur and Kurram.
The leaders decided to send a 60-member delegation to Kabul to urge Afghan President Hamid Karzai to take up the matter with Pakistan through diplomatic channels.
The UN refugee agency has said that it supported the relocations as clashes between suspected al-Qaida members and Pakistani security forces had made it "impossible" to assist the refugees properly.
About three million Afghans are still living in Pakistan, more than 25 years after the 1979 Soviet invasion forced millions of Afghans to flee to Pakistan and Iran.