The Taliban offered to hold talks with South Korean officials in Afghan government-controlled territory over the fate of 21 hostages if the UN guaranteed the safety of the militant delegation.
Friday's offer, made by a purported Taliban spokesman, came as Afghan President Hamid Karzai traveled to the US for weekend talks with US President George W. Bush expected to address the hostage crisis.
South Korea expressed hope on Friday that the summit would help efforts to win the release of the 16 Korean women and five men abducted on July 19 in Ghazni Province. The Taliban have already shot and killed two men in the church group, which was doing voluntary health work in Afghanistan.
Qari Yousef Ahmadi, a purported spokesman who claims to speak for the Taliban, said the militants were ready to negotiate anywhere for the freedom of the captives with South Korea's ambassador to Afghanistan -- if the UN mission guarantees the militant delegation's safety.
"The Taliban are ready to meet them in Kabul, other cities or other country, but only under one condition and that is that the UN guarantees their safety," Ahmadi said, speaking on telephone from an undisclosed location.
Officials from the UN mission in Afghanistan were not immediately available to comment on Ahmadi's offer.
South Korean presidential spokesman Cheon Ho-sun declined to comment on Friday on whether South Korean negotiators planned face-to-face talks with the Taliban, repeating an earlier remark that the country has been "maintaining direct and indirect contacts" with the captors.
"What we want to tell [the kidnappers], the primary goal of these contacts is to make it clear that there is a limit in our government's ability to address the release of prisoners they demand," Cheon told a press briefing in Seoul.
South Korea has sent lawmakers to lobby the US to help resolve the crisis. Seoul has asked Washington and Kabul to exercise "flexibility," as negotiations to free the captives are deadlocked over the Taliban's demand that insurgent prisoners be freed, including some in US custody.
A group of local doctors, meanwhile, traveled from Kabul to Ghazni in a hope of being able to reach the hostages, and treat those in a need of medical care.
However, militants did not allow the doctors to cross into their territory on Friday, telling the group they suspect spies to be among them, said Mohammad Hashim Wahaaj, who is leading the delegation.