North Korean leader Kim Jong Il left north-eastern China on Saturday after visiting a city close to the border with North Korea, Chinese state media said, according to dpa. Speaking in Tonghua city, Kim "praised the achievements made by China's north-eastern region in adjusting industrial structure and transforming the economic growth mode", the official Xinhua news agency reported. South Korea's Yonhap news agency said witnesses saw Kim's special armoured train cross from China into North Korea at about 5 pm (0900 GMT). On Friday, Kim told China's top diplomat, Dai Bingguo, that he remained committed to talks on ending his nation's nuclear weapons programme, two days after he made a similar pledge to Russian President Dmitry Medvedev. Kim arrived in north-eastern China late Thursday after travelling along a Trans-Siberian rail route from the Siberian city of Ulan-Ude, where he met Medvedev on Wednesday. Previous trips abroad by Kim were not officially reported until he had returned to North Korea. But Chinese, Russian and even North Korean media have confirmed many details during his latest trip. China's Global Times newspaper on Friday said confirmation by North Korea's state news agency KCNA of Kim's visit to Russia and his return to Pyongyang via China was "clearly different from previous trips." Kim met President Hu Jintao in May during his previous visit to China, but Dai was the top Chinese official he met on his latest trip.