High-ranking military officials between South Korea, Japan and the United States will hold tripartite talks in Washington next month to discuss defense coordination against nuclear and missile threats from the Democratic People's Republic of Korea (DPRK). Army Col. Wi Wong-seop, vice spokesman at the South Korean Defense Ministry, told a routine press briefing that the sixth round of the Defense Trilateral Talks among the three allies will be held for two days from April 17 in Washington D.C. Wi said during the annual security cooperation dialogue, delegations from the three allies will discuss how to cooperate in the DPRK's nuclear and missile threats as well as transnational nonmilitary threats such as humanitarian and disaster relief. The defense dialogue was launched in 2008 to let deputy defense ministerial-level officials from the three nations talk about ways to coordinate in security issues. The sixth round came as a follow-up action to the trilateral summit between South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe under the arbitration of U.S. President Barack Obama. During the summit held on the sidelines of the Nuclear Security Summit in the Netherlands earlier this week, the three heads of state agreed to hold tripartite talks among top nuclear envoys who represent the long-suspended six-party talks, stressing the need for the senior-level defense dialogue. South Korea had yet to appoint its top delegate to the six-way dialogue. The post remained vacant after the former envoy Cho Tae- yong was promoted to vice foreign minister in late February. Tensions escalated in the Korean Peninsula as the DPRK launched two medium-range ballistic missiles Wednesday morning. Those were believed to be Rodong missiles capable of carrying nuclear warhead. The Rodong missiles, which flew about 650 km and landed within waters of Japan's air defense identification zone, were launched for the first time in around five years, and were fired for the first time from mobile launchers. It followed several firings of short-range missiles and rocket- propelled artillery shells over the past weeks in what appeared to be in protest against the joint annual military exercises between South Korea and the United States. The "Key Resolve" command post exercise, which began on Feb. 24, ended on March 6, but the "Foal Eagle" field training exercise will last until April 18 despite the DPRK's earlier call for delay or cancellation of the drills, which Pyongyang has denounced as the rehearsal for a northward invasion.