Seoul, Jan 27 : The leaders of the South Korean military and US Forces Korea (USFK) on Thursday discussed ways to bolster their combined deterrence posture against North Korea following Pyongyang's recent series of missile tests, the Joint Chiefs of Staff (JCS) said. JCS chairman Gen Won In-choul had a closed-door meeting with USFK commander Gen Paul LaCamera, hours after the North fired two apparent short-range ballistic missiles toward the East Sea, the sixth such launch this year, Yonhap news agency reported. They exchanged views on Pyongyang's recent missile tests and reaffirmed the alliance between the two nations, the JCS said. Later in the day, Won visited the Air Force Operational Command at Osan Air Base, south of Seoul, and held a video conference with commanders in charge of anti-missile strategies to stress the robust readiness, it noted. The latest move was seen as part of efforts to assuage public security concerns over Pyongyang's flurry of missile tests at the start of the year. The North apparently test-fired at least two cruise missiles from an inland area on Tuesday following four reported rounds of weapons tests, including hypersonic missile launches on January 5 and 11. It also tested the KN-23 missile, modelled after Russia's Iskander ballistic missile, on January 14 and its own version of the US Army Tactical Missile System (ATACMS), called the KN-24, three days later. /IANS