China's President Xi Jinping pledged to make concerted efforts with South Korea's President Moon Jae-in to address differences between the two countries properly, the official Xinhua news agency said on Thursday. 'Xi made the remarks in a congratulatory message sent to Moon on the 25th anniversary of the establishment of China-South Korea diplomatic relations,' Xinhua said. Development of China-South Korea relations makes a positive contribution to regional peace and development, Xinhua cited Xi as saying. The news agency did not provide further details.