N. Korea ups slander against S. Korean president

North Korea has drastically stepped up its smear campaign against South Korean President Lee Myung-bak, Seoul\'s Unification Ministry said Thursday, in an apparent sign of growing frustration over the inter-Korean impasse. The North frequently accused Lee of being a \"traitor\" and \"stooge serving the U.S.\" for what Pyongyang claims is South Korea\'s hostile policy toward the North and Seoul\'s subservience to Washington. The North\'s official Korean Central News Agency usually carries articles full of slander on Lee and threats against South Korea almost every day. The cases of the North\'s slander on Lee has jumped to 166 in June from 64 in May when Lee offered to invite North Korean leader Kim Jong-il to next year\'s international security summit in Seoul, the ministry said. Lee unveiled the offer during a trip to Berlin in May on condition that Pyongyang firmly commits to nuclear disarmament and apologizes for last year\'s two deadly attacks on the South. North Korea has refused to take responsibility for the sinking of a South Korean warship and shelling of a frontline South Korean island, keeping the two sides from moving their relations forward. In what could be a sign of frustration over the lack of progress in inter-Korean ties, the North has recently vowed not to deal with \"traitor Lee Myung-bak\" and to attack the South for anti-Pyongyang \"psychological warfare.\" It\'s not unusual for the North to denounce leaders of South Korea and its key ally, the United States. In 2009, a North Korean Foreign Ministry spokesman described U.S. Secretary of State Hillary Clinton as \"a primary schoolgirl\" and \"a pensioner going shopping\" in response to her criticism to Pyongyang\'s nuclear weapons programs. Clinton likened North Korea\'s leaders to \"unruly teenagers\" who seek to gain U.S. attention through nuclear and missile activities.