The remaining hostages are said to be seriously ill.
On Saturday, the AFP news agency reported it has received a phone call from a woman, purported to be one of the 21 hostages.
"I don't want to die. We want to go home," she said in English. "I don't know how long we can survive."
In South Korea, the body of Shim Seong-Min, the second hostage to be killed by the Taliban, was laid to rest.
Ali Shah Ahmadzai, Ghazni's police chief said: "Talks are going on to find an agreement on location. We are in favour of dialogue, that's what logic requires."
"If that doesn't work, then force may be used," he said.
There has been a build-up of Afghan forces in Ghazni since the hostages were taken from a bus on the main road from Kabul to Kandahar in the south on July 20.
But, General Zahir Azimy, an Afghan military commander, said: "Launching an operation to rescue the hostages is not up for discussion, the presence of our troops there is not for launching rescue operations."
Chun Ho-sun, the South Korean presidential spokesman, said: "Through our contacts, our foremost goal is to make it clear that there is a limit as to what our government can do to meet their demands of releasing the prisoners."
The Afghan government has refused to release prisoners in exchange for the hostages and the US has said it will "not make concessions to terrorists".
A German engineer and four Afghans kidnapped a day before the Koreans are also still being held by the Taliban, who are demanding Germany withdraw its 3,000 troops from Afghanistan. Berlin has flatly rejected the demand.
Meanwhile, also in Afghanistan on Saturday, two Afghan civilians were killed after a suicide car bomb hit foreign troops in the southern city of Kandahar.
Afghan troops said that two foreign soldiers were also wounded.