The senior South Korean presidential secretary for security affairs, Baek Jong-chun, arrived Friday in Kabul, where Korean officials say he is to work with Afghan President Hamid Karzai on saving the lives of the 22 hostages. South Korean President Roh Moo-hyun has canceled his upcoming summer vacation to focus on the crisis.
Taleban insurgents killed a 42-year-old Christian pastor Wednesday, a week after they kidnapped him and 22 other South Korean Christian activists.
Another deadline passed Friday, after which a man calling himself a Taleban spokesman told several reporters remaining hostages would be killed if the militants' demands were not met.
In a phone call with reporters, female hostage Lim Hyun-joo said the kidnappers' demands are twofold.
Speaking in Dari in the presence of her captors, Lim says the Taleban want money from South Korea, and the release of Taleban comrades from Afghan prisons.
Switching to her native Korean, Lim made an impassioned plea for action.
She begs for help in ending the crisis, and says all of the hostages are sick.
The hostages traveled to Afghanistan in defiance of a South Korean government ban, and there has been criticism of them here in Korea for putting themselves in a dangerous position.
Several hundred South Korean military and civilian personnel provide non-combat support to multinational stabilization efforts in Afghanistan. However, prior to the abductions, Seoul had announced those personnel would be withdrawn by the end of the year.