Pakistani Taliban leader Hakimullah Mehsud has told the BBC he is open to "serious talks" with the government but says he has not yet been approached.
In a rare interview, he denied carrying out recent deadly attacks in public places but said he would continue to target "America and its friends".
The chief loosely controls more than 30 militant groups in the tribal areas.
After being elected PM in May, Nawaz Sharif announced he would open unconditional talks with the Taliban.
The group has killed thousands of people in its war against the Pakistani state in recent years.
They control areas in the north-west and have been blamed for a wave of suicide bombings and other attacks.
'End drone strikes'
The interview with Hakimullah Mehsud was conducted by the BBC's Ahmed Wali Mujeeb this month in an undisclosed location in the north-western tribal areas.
Asked about the possibility of peace talks with the government, Mehsud said: "We believe in serious talks but the government has taken no steps to approach us. The government needs to sit with us, then we will present our conditions."
Mehsud said he was not prepared to discuss conditions through the media.
"The proper way to do it is that if the government appoints a formal team, and they sit with us, and we discuss our respective positions."
Mehsud said he would guarantee the security of any government negotiators.
He said that for any ceasefire to be credible "it is important that drone strikes are stopped".
The second-in-command of the Pakistani Taliban, or Tehrik-e-Taliban Pakistan, Waliur Rehman, was reportedly killed in a suspected US drone strike in May.
When pressed on why previous peace initiatives had failed, Mehsud blamed the government.
He said: "The government of Pakistan bombs innocent tribal people due to the pressure of America... Drone strikes conducted by Americans were [backed] by Pakistan. Then the Americans pressed Pakistan to start ground operations in these areas, and Pakistan complied.
"So the government is responsible for past failures."
Mehsud has a $5m FBI bounty on his head and is thought to be responsible for the deaths of thousands of people.
But in the interview he denied carrying out recent deadly attacks in public places.
He said: "We consider the safety of Muslims, of scholars, of mosques and madrassas as our sacred duty.
"As for explosions which cause damage to the life and property of Muslims, we have denied any link in the past, we deny any link today."
Mehsud added: "We have targeted those who are with the infidels, America, and we will continue to target them."
When asked again whether there would be any conditions for talks, Mehsud said he would not discuss this in the media.
However, when asked about the withdrawal of US-led troops from Afghanistan at the end of next year, he said: "America is one of the two reasons we have to conduct a jihad against Pakistan. The other reason is that Pakistan's system is un-Islamic, and we want it replaced with an Islamic system.
"This demand and this desire will continue even after the American withdrawal."
The BBC's Aleem Maqbool in Islamabad says that whether it is the imminent withdrawal of coalition troops from Afghanistan or the Pakistani government's moves to open dialogue, there is an impression that the militants of this region feel that they have the upper hand.
It is clear that Hakimullah Mehsud believes he can now call the shots, he says.
As far as denying bomb attacks, our correspondent says that either the Taliban did carry them out or Mehsud is not in control of the militants - so in either case the question is, why bother talking to him?
After Mr Sharif's announcement that the government would open unconditional talks with the militants, the Taliban issued a list of demands, including the imposition of Sharia (Islamic law).
Attacks on the security forces have continued, prompting army chief Gen Pervez Kayani to warn that the military would not allow the Taliban to set conditions for peace.
Violent attacks on public places escalated last month, with the north-western city of Peshawar the worst hit.
The bombing of a church in September left dozens dead, while more than 40 were killed a week later in an attack on a market in the city.
Hakimullah Mehsud came to prominence in 2007 as a commander under then Taliban leader Baitullah Mehsud, with the capture of 300 Pakistani soldiers adding to his prestige among the militants. He led a campaign of attrition against the Pakistani army and Nato convoys heading to Afghanistan.
After Baitullah Mehsud was killed in a US drone strike in August 2009, Hakimullah was appointed leader.
Several claims of his death made by US and Pakistani intelligence sources have proven untrue.
There remains great suspicion among Western powers that any peace moves with the Taliban simply give the militants more time to regroup.
Pakistan's interior and foreign ministry were contacted about Hakimullah's interview but declined to comment.