Police are under pressure in Dagar, Buner's main town
Officials in North West Frontier Province in Pakistan are meeting to discuss a peace deal with the Taleban that has sparked deep US concern.
The peace deal was intended to introduce Sharia law in some north-west districts in return for an end to the Taleban insurgency.
However, the Taleban have not laid down their arms and are expanding influence.
The US has accused officials in Pakistan of abdicating control to the Taleban in the north-west.
The peace deal covers the six divisions of Malakand, including the troubled Swat region.
The Taleban have almost full control of Swat and this week have been consolidating operations in Buner, just 100km (62 miles) from the capital, Islamabad.
Separately, the army said it had killed 11 militants in the Orakzai agency, said to be home to groups loyal to South Waziristan's Taleban leader Baitullah Mehsud.
Ahead of the meeting, North West Frontier Province spokesman Iftikhar Hussain said: "Those who took arms must lay them down. Those who went to Buner, they must get out from Buner.
"This is the only way, and we are asking them for the last time."
The BBC's M Ilyas Khan in Islamabad says the North West Frontier Province government feels it has fulfilled its part of the deal by enforcing Islamic courts in the region but that the Taleban have yet to meet their end of the bargain.
They were expected to lay down their arms and allow police and other officials to resume their duties.
However, the Taleban have further consolidated their hold on Buner, beating back an attempt by government troops to enter the region.
A paramilitary convoy that arrived in the border village of Totalai had to abort its plans to reach Buner's central town of Dagar.
On Tuesday, six judges of the lower judiciary in Buner went on emergency leave to avoid possible Taleban attacks.
On Thursday, at a tribal meeting attended by Buner elders, the local administration and the Taleban, the Taleban agreed not to display their arms in Buner and to reduce their checkpoints to a minimum number. However, our correspondent says putting this into practice may not be easy.
A meeting in Buner brought a Taleban agreement not to display arms
He says the Taleban have crushed all opposition in Buner and have strengthened local membership with more recruitment.
The US has expressed deep concern over the developments.
On Wednesday, Secretary of State Hillary Clinton said Pakistan posed a "mortal threat" to the world by abdicating to the Taleban.
On Thursday US Defence Secretary Robert Gates warned Pakistan that relations with the US would be threatened unless Islamabad combated the rise of the Taleban.
In the Orakzai operation, the army said militants were targeted in the Chapari Ferozkhel, Khwaja Khizr and Bizoti areas.
Other operations on Tuesday and Wednesday killed 27 militants, it said.
Groups loyal to Baitullah Mehsud are suspected of targeting Nato supply trucks heading to Afghanistan.