N. Korea: We will take "merciless measures" to defend coast from S. Korea

N. Korea threatens to ta

North Korea warned Friday that it would "will take merciless military measures" to defend itself in disputed waters where a bloody naval clash with rival South Korea took place this week, further raising tensions ahead of a visit to Seoul by US President Barack Obama. North Korea reiterated it would not honor the Northern Limit Line, a de facto western sea border drawn up by the UN command at the end of the 1950-53 Korean War, also demanding that South Korea apologize over the clash in which one North Korean naval officer was killed and three others wounded. South Korea's defense ministry said its position on the sea border remains unchanged. In related news, French Pyongyang envoy Jack Lang stated on Friday that talks with North Korean officials during his five-day visit to the city were "intense, frank and cordial."