Kim gave that assurance Thursday to visiting Wang Jiarui, head of the International Department of the Communist Party of China Central Committee, China's official Xinhua news agency reported.
Kim said it is the unswerving will of his government and the Workers' Party of Korea to carry on the legacy of the late Kim Jong Il, to deepen the traditional friendship with China, the report said. At home, Kim said the goal of his government is developing the economy and improving people's livelihood, the report said.
China has been the closest ally of the isolated Communist country, whose leader Kim Jong Un took over after the death of his father in December.
Wang was quoted as telling his host China views relations with North Korea from a strategic and long-term prospective, Xinhua reported. He said the two sides should enhance strategic communication and coordination on major global and regional issues and make unremitting efforts to safeguard peace and stability on the Korea Peninsula.
Late last month, North Korea denied any policy change in the country under Kim's leadership.
A spokesman for the Committee for the Peaceful Reunification of Korea said "hostile forces" have been "trumpeting 'reform and opening' to impose their corrupt system" on North Korea and such forces now have "hallucination that such move is taking place" in the country.
He said his country is "putting forward new strategic and tactical policies in keeping with the changing and developing situation," but stressed the current leadership has not "broken with the past."
North Korea also has said it will continue with its nuclear program, while warning the United States shouldn't seek to underestimate North Korea's determination.