North Korea has also stepped up weapons testing activity as its leader Kim Jong Un expands his military nuclear program. SEOUL, South Korea (AP) — South Korea flight-tested on Thursday its first domestically developed hypersonic weapon, designed to fly at least five times the speed of sound and evade missile defense systems, bringing Seoul closer to what it says could be game-changing weapons capabilities. South Korean President Lee Jae Myung attended the test, saying it's a major step in strengthening the country’s conventional defense capabilities, according to a statement. Lee has also called for strengthening South Korea’s conventional defense capabilities while reducing its reliance on the United States, which unilaterally decided to scale back a major military exercise with the South in August, with Trump citing his “very good relationship” with Kim. In its latest weapons test on Oct. 3, North Korea launched what it described as a hypersonic intermediate-range missile that it said flew more than 1,000 kilometers (621 miles).