In an interview late on Sunday with The Associated Press, the commander, Mullah Dadullah, ruled out any reconciliation with the government of Hamid Karzai, the Afghan president who is backed by the US, and claimed that the country's new parliament, its first in more than 30 years, inaugurated last week, was "obedient to America".
Dadullah spoke to the AP via satellite phone from an undisclosed location. He said he was inside Afghanistan.
"More than 200 Taliban have registered themselves for suicide attacks with us which shows that a Muslim can even sacrifice his life for the well-being of his faith. Our suicide attackers will continue jihad (holy war) until Americans and all of their Muslim and non-Muslim allies are pulled out of the country," he said.
Dadullah, who lost a leg fighting for the Taliban during its rise to power in the mid-1990s, is one of the group's top commanders, responsible for operations in eastern and southeastern Afghanistan and, as such, a man wanted by the US-led force hunting Taliban and al-Qaida fighters.
Dadullah implied that the Taliban and al-Qaida were working together, and said mujahidin from various parts of the world, including Arabs, were fighting in Afghanistan.
He said the foreigners made up about 10% of the fighters.
"Both Taliban and al-Qaida have the same objectives," he said, warning that anyone supporting the Americans and the government "will be dealt with".
The Taliban may be borrowing
tactics used by Iraqi fighters
However, General Mohammed Zahir Azimi, a spokesman for Afghanistan's Defence Ministry, dismissed on Monday Dadullah's claims of Taliban strength as "propaganda" and said Afghanistan had enough security forces to deal with the fighters.
"The Taliban are isolated. The Taliban have no power. They are using land mines and terror activities ... or suicide attacks. These kind of operations show they are not strong and that they are weak," Azimi told the AP.
The Taliban government was toppled by US-led forces in late 2001 when it refused to turn over al-Qaida leader Osama bin Ladin and stop offering a haven to the group following the 11 September 2001 attacks on the US.
Upsurge of violence
The past year has seen an upsurge of violence in the volatile southern and eastern regions. More than 1500 people have died nationwide, many of them Taliban fighters - the heaviest toll in the past four years.
In recent months there has been a spate of human-bomb attacks in Afghanistan, including one in Kabul in September outside an Afghan army training centre that killed nine people.
The attacks have fuelled fears that the insurgents could be adopting tactics used in Iraq.
"Our suicide attackers will continue jihad (holy war) until Americans and all of their Muslim and non-Muslim allies are pulled out of the country"
Mullah Dadullah, Taliban commander
US military officials in Afghanistan could not immediately be reached for comment Monday on Dadullah's remarks.
Karzai has encouraged Taliban members to leave the ultra-conservative group, renounce terrorism and go through a formal reconciliation programme.
So far, several hundred rank-and-file members and some 50 senior officials have done so, including some who ran in September's parliamentary elections.