Baitullah Mehsud has an aversion to publicity and photographs
A top Taleban commander in Pakistan has halted peace talks with the government, his spokesman says.
Last week Baitullah Mehsud ordered a ceasefire amid reports that he was close to reaching a peace deal with the new government.
But his spokesman says talks have broken down because the government refuses to order troops out of the tribal areas by the Afghan border.
The government says it will deal with militants by dialogue and development.
Baitullah Mehsud is the man the Pakistani authorities say ordered the killing of former Prime Minister Benazir Bhutto.
"The government refused to pull out its forces from the tribal areas which forced Mehsud to call off the talks," Mehsud's spokesman Maulvi Omar, told the AFP news agency.
However the spokesman said that they did not plan to start fighting again at this stage.
"Taleban remain firm in the ceasefire but Mehsud warned that if the government launched any action his fighters would retaliate," Maulvi Omar said.
The BBC's Barbara Plett in Islamabad says it is not clear if this is a negotiating tactic, or the collapse of talks that appeared close to agreement.
Local newspapers have published drafts of a 15-point deal that calls for an end to militancy, an exchange of prisoners and a redeployment of the army.
Last week Mehsud's fighters issued pamphlets containing his order for his fighters to stop fighting. They said that anyone found violating the order would be punished.
Baitullah Mehsud's stronghold is in South Waziristan, an area that has seen many of the heaviest clashes between militants and the security forces in recent years.
American officials cautiously support the new government's efforts to reach peace through talks.
Our correspondent says that previous deals have turned the tribal areas into a sanctuary for Taleban and al-Qaeda-linked militants from where they have launched attacks in Afghanistan.
They also began hitting Pakistani targets when the army tried to stop them.
Baitullah Mehsud is said to command about 20,000 pro-Taleban militants and a majority of them belong to the Mehsud tribe.
The previous government, that supported President Musharraf, said it had evidence from phone intercepts that Mehsud had organised the killing of former Prime Minister Benazir Bhutto in Rawalpindi in December.
He denies the charge.