The hardline movement's spokesman, Yousuf Ahmadi, had said a week ago that the Taliban were ready to respond positively to President Hamid Karzai's renewed offer of negotiations.
But Ahmadi appeared to be stepping back from that stance by adding the apparently new condition involving the withdrawal of foreign soldiers from the insurgency-hit country.
"If these talks... rescue our country's independence and result in finding a way for the withdrawal of foreign forces, [Taliban] are ready to participate," Ahmadi said in a statement.
But he said that the Taliban did not believe the Afghan government had the authority to meet such conditions.
"Forcing the crusader forces out of the country has been one of the most important goals of the Taliban in the past six years since they've invaded our territory," he said.
There are about 39,000 mostly Western soldiers in Afghanistan under NATO command and around 15,000 in a separate US-led coalition. The soldiers are helping to defeat a Taliban insurgency and facilitate sorely needed reconstruction.
Mr Karzai made a new offer of talks with the insurgents on September 9.
He has regularly offered negotiations with the Taliban. The hardliners were in government between 1996 and 2001, and there have been rumours that contact has already been made.
The president has also said the radical Hizb-i-Islami faction of former prime minister Gulbuddin Hekmatyar, which is fighting the government and its allies separately from the Taliban, is welcome to join a peace process.
The faction has responded that it would only meet the government if the international forces leave the country. © 2007 Australian Broadcasting Corporation
