SEOUL, South Korea — North Korea has tested a new tactical weapon, the North’s official news media said on Friday, reporting that Kim Jong-un witnessed the event in his first publicized visit to a weapons test site since the country test-launched its intercontinental ballistic missile last November. State media did not identify the weapon, and the test did not appear to violate the voluntary moratorium North Korea imposed on nuclear and long-range ballistic missile tests this year. Still, Mr. Kim’s renewed activities at weapons test sites could complicate the already stalled talks between North Korea and the United States over...