Talks to free 21 South Koreans kidnapped by Taliban insurgents in Afghanistan were deadlocked yesterday, with still no agreement on where face-to-face negotiations might take place.

The Taliban have killed two of the hostages and have repeatedly threatened to kill the remaining 18 women and three men unless the Afghan government agrees to free jailed rebels.

Afghanistan has refused to release Taliban prisoners, saying that would encourage a kidnapping ?industry?. ?We will not do anything that will encourage hostage-taking, that will encourage terrorism. But we will do everything else to have them released,? Afghan President Hamid Karzai told CNN ahead of his visit to the United States where he is holding two days of security talks with US President George W. Bush.

South Korea has proposed holding face-to-face talks with the Taliban as a way of breaking the impasse, but a new apparent deadlock over where to hold the talks has emerged.

Taliban kidnappers have demanded the meeting take place in territory they control or under a United Nations guarantee for their safety if held elsewhere. But after four days of talks on where to hold negotiations, there were few signs of progress.