"Don't Speak in Korean": When Koreans Travel to North Korea

Only a few minutes after arriving in Dandong, a Chinese city that borders North Korea, my assumptions about travel to North Korea were abruptly shattered. I was told by a Chinese employee of the tour company that it would not be wise to, while in North Korea, speak Korean or let anyone know that I am half Korean. This employee told me that South Korean-style pronunciation was regarded with suspicion in the North, and that the Chinese tour company could not guarantee my safety if it became known