Seoul, South Korea (CNN) -- North Korean leader Kim Jong Un ordered his troops to be on the highest alert Sunday as he visited the DMZ, or demilitarized zone between North and South Korea.
In his first reported visit to the tense border since taking control of North Korea last December, KCNA, the state-run news agency, said the young leader had visited "the biggest hotspot where the gunfire could be heard anytime due to the reckless provocations of the enemies."
The visit comes amid heightened rhetoric from Pyongyang, with recent threats of a "sacred war" against Seoul and Washington. Current joint military drills between the United States and South Korea have been condemned by the North as a provocation. The United States says the drills are defensive in nature.
About 150,000 North Koreans protested at the Kim Il Sung square in Pyongyang on Sunday to condemn the South, according to South Korean media.
North Korea's KCNA reported a South Korean army unit hung portraits of the late leader Kim Jong Il and the founder of North Korea, Kim Il Sung, on walls and doors of a military base and wrote "unspeakable defamatory words below them."
Asked by reporters about the presence of such posters, Defense Ministry spokesman Kim Min-seok said, "For South Korean soldiers fighting at the front line, it's important for them to be armed with a proper mindset against the enemy. I believe the posters were placed to encourage this spirit, so responding to the North's criticism on this matter is not appropriate."