South Korea is developing strategies against potential chemical and biological attacks by the Democratic People\'s Republic of Korea (DPRK), the South Korean defense minister said Friday. The country has yet to develop its own vaccines against such threats, Kim Kwan-jin said during a parliamentary audit, citing the prohibitive costs. \"We don\'t have an exact date for the completion of the development, but once vaccines are in place, there should be no big problems,\" he said. The U.S. forces in South Korea and the health authorities here do have anthrax vaccines, according to the minister. South Korean and U.S. forces conduct joint exercises aimed at detecting, identifying and neutralizing chemical and biological weapons, Chairman of South Korea\'s Joint Chiefs of Staff Han Min- koo added. South Korea\'s latest defense white paper estimates the DPRK possesses some 2,500 to 5,000 tons of chemical agents.