South Korea's top military officer has canceled his trip to the United States this week amid heightened cross-border tensions due to North Korea's explosions of major roads connecting the two Koreas, sources said Wednesday. Joint Chiefs of Staff Chairman Adm. Kim Myung-soo initially planned to depart for the United States on Tuesday to attend a senior-level meeting, but has decided to hold virtual talks instead in light of the recent security situation, according to the sources. On Tuesday, the North Korean military blew up parts of the western Gyeongui and eastern Donghae roads just north of the Military Demarcation Line that bisects the two Koreas. "Considering the situation where North Korea is increasing threats against the South, such as blowing up the Gyeongui and Donghae Lines, the in-person meeting was changed to a virtual one to maintain readiness," one of the sources said. The North's explosions came after its military announced last week that it will cut off all roads and railways linked to Sou th Korea and build front-line defense structures to "completely separate" the North's territory from the South. Late last year, North Korean leader Kim Jong-un defined inter-Korean relations as those between "two states hostile to each other," and said there is no point in seeking reconciliation and unification with South Korea. Tensions have also run high after the North claimed last Friday that the South flew drones over Pyongyang multiple times this month. South Korea's military has declined to confirm the North's claim. Source: Yonhap News Agency