China, Japan and Republic of Korea (ROK) inked Tuesday the Memorandum of Cooperation on the Mechanism of Ministerial Meeting to boost trilateral cooperation on water challenges. Chen Lei, China's Minister of Water Resources, Okuda Ken, Senior Vice Minister of Land, Infrastructure, Transport and Tourism of Japan, and Han Man-Hee, Vice Minister of Land, Transport and Maritime Affairs of the Republic of Korea, attend the signing ceremony during the Sixth World Water Forum in Marseille, France. [Xinhua photo]