Trade between the Koreas ` ` serves the common interest of all parties , '' an official says . Yoshihiko Noda visits Beijing for the first time as Japanese prime minister . Kim 's death was announced by Pyongyang on December 19 and has put the region on edge , as the world waits to see how North Korea 's succession will play out . China and Japan also signed energy and environmental agreements . Both countries will also use their own currency -- not the U.S. dollar -- in bilateral trade .
Trade between the Koreas ` ` serves the common interest of all parties , '' an official says . Yoshihiko Noda visits Beijing for the first time as Japanese prime minister . China and Japan also signed energy and environmental agreements . Both countries will also use their own currency -- not the U.S. dollar -- in bilateral trade .