Taleban leader Mullah Mohammed Omar would refuse any offer of an amnesty from the Afghan government, a Taleban spokesman is reported as saying.
The US says Mullah Omar must pay for his crimes
"We don't need any guarantee of safety," Taleban spokesman Abdul Latif Hakimi told the Reuters news agency.
On Monday the head of Afghanistan's reconciliation commission called on Mullah Omar to be included in an amnesty for Taleban fighters.
Mullah Omar has been in hiding since the fall of the Taleban in 2001.
Mr Hakimi was in defiant mood when he spoke to Reuters.
"On [Mullah Omar's] orders, we have increased attacks on US forces in recent weeks and will continue this," he said.
The US military says scores of insurgents have been killed in the last seven days as well as two US soldiers and a number of Afghan soldiers.
The government has been running an amnesty programme for Taleban fighters but it excludes senior figures or those guilty of what are deemed to be serious abuses of human rights.
However, the head of Afghanistan's independent peace and reconciliation commission, Sibghatullah Mojaddedi, has called for a widening of the amnesty.
He now says that Mullah Omar and renegade warlord Gulbuddin Hekmatyar should be accepted back by the government if they renounce arms.
"Our terms are if they lay down their weapons, respect the constitution and obey the government, we don't have big conditions for them," he said on Monday.
It is not clear if President Hamid Karzai supports offering an amnesty to Mullah Omar.
Mr Mojaddedi said his policy had been cleared with the Afghan government. But Mr Karzai has still not commented on the idea.
The US military appears to be against the proposal.
But US military spokesman Col James Yonts said on Monday: "Our position all along has been that those guilty of serious crimes must be responsible for their actions,
"We believe the government of Afghanistan understands and supports that."