South Korean and Afghan officials were determining Thursday where to convene face-to-face negotiations with the Taliban over the release of South Korean hostages, a chief negotiator said.
There are 21 South Korean missionaries still captive after their kidnap on July 19. They were traveling by bus from Kabul to the southern city of Kandahar.
Two others were killed after Taliban demands for the release of militant prisoners were not met.
The upcoming meeting with the Taliban was agreed to after another deadline passed Wednesday.
Meanwhile, a delegation of eight South Korean lawmakers was en route to Washington Thursday to meet with House Speaker Nancy Pelosi, Undersecretary of State Nicholas Burns and Stephen Hadley, the national security adviser, in hopes of obtaining the United States' help in negotiations.
"We will sincerely plead with the United States to take more substantial and meaningful measures to resolve this crisis," Rep. Cheon Young-se of the liberal Democratic Labor Party said before the delegation set off.
The delegation also plans to meet U.N. Secretary-General Ban Ki-moon, South Korea's former foreign minister.
Earlier South Korean diplomatic efforts failed to bend Afghanistan's refusal to respond to Taliban demands for the release of militant prisoners.
Taliban captors have agreed to meet with South Korea's ambassador but have not found a suitable place, said Waheedullah Mujadidi, head of a delegation negotiating with the Taliban.
A purported Taliban spokesman, Qari Yousef Ahmadi, denied the South Koreans had requested direct talks with the militants. But he said the militants would be willing to hold such a meeting in Taliban-controlled territory.
The Taliban "want to negotiate directly with the Koreans because the Kabul administration is not sincere about releasing the Taliban prisoners," Ahmadi said.
Ahmadi said the remaining hostages were still alive.
On Wednesday, Afghan army helicopters dropped leaflets warning citizens of upcoming military action in Ghazni province, where the church group was kidnapped.
Defense Ministry spokesman Gen. Zahir Azimi said the mission, days or weeks away, had long been planned and had no connection with the hostage crisis. But a show of military force in the region could put the kidnappers under further pressure.
From NPR reports and The Associated Press