Simultaneously, the news agency, quoting sources, said South Korean officials were talking to the Taliban to decide on a venue for face-to-face talks about the hostages, most of whom are reported quite ill since being abducted on July 19 and held prisoner in the central Afghanistan town of Ghazni.

The sources told the agency the militants, who have already killed two hostages, agreed to meet with the South Korean ambassador but the venue has not been fixed.

The indication about the use of force as an option came after some South Korean lawmakers met with U.S. leaders in Washington to seek their help, the report said. "All pressures need to be applied to the Taliban to get them to release these hostages," U.S. Assistant Secretary of State Richard Boucher was quoted as saying.

The Taliban have demanded the release of its prisoners in exchange for freeing the hostages but the U.S.-supported Afghan government has so far refused to accept it.