South Korea's defense ministry on Thursday refuted a claim by North Korea's missile chief that questions Seoul's recent test launch of a hypersonic glide vehicle (HGV). Earlier in the day, Jang Chang-ha, director-general of North Korea's Missile Administration, claimed that South Korea's test of the HGV may not have achieved hypersonic flight because its outside appearance was "not stained with any soot," according to the North's Korean Central News Agency. Jang cited photos provided by South Korea after last Thursday's test, but Seoul's defense ministry countered by saying the vehicle has advanced thermal-protection technology and the visible appearance of "soot" is impossible during hypersonic flight. South Korea's military "plans to further develop technologies involved in the weaponization process of the HGV," the ministry said. In a rare public disclosure of the development of key military assets, Cheong Wa Dae unveiled South Korea's first test launch of the HGV. The test came amid rising inter-Korean tensions following the recent explosion of a land mine in the border area that inju