The article discusses Pence's visit to the DMZ, a strip of land that separates North and South Korea, and is heavily occupied by military troops. Pence's visit comes within a day after North Korea's "Day of the Sun", where, among a parade, they displayed new nuclear warheads. They also attempted another test launch, but the test missile exploded on launch. President Trump used his visit with China's Xi Jinping to discuss North Korea's actions, and applauded China's refusal to accept North Korean coal ships. U.S. national security adviser H.R. McMasters says that the North Korean threat may be coming "to a head."