Chinese Vice President Xi Jinping left Beijing for Pyongyang Tuesday morning, kicking off an official good-will visit to North Korea aimed at boosting bilateral cooperation and the traditional friendship between the two nations.

The China-N Korea friendship has acquired new elements and improved steadily in the 21st century.

Established almost 60 years ago, the friendship was created and fostered by earlier generations in either country and has stood the test of time, being cherished as a great treasure by both sides.

Top leaders of the two nations have met often in recent years and agreed to develop bilateral ties on the principles of "carrying forward traditions, aiming at the future, being good-neighborly and friendly, and strengthening cooperation."

Chinese leaders Hu Jintao, Wu Bangguo and Li Changchun, as well as former Chinese President Jiang Zemin, visited North Korea over the past few years, while top North Korean leader Kim Jong Il has visited China four times since 2000.

These frequent visits have strengthened trust and understanding between the two peoples, and enlarged bilateral exchanges and cooperation in every field, providing impetus to the already warm mutual ties.

Cooperation in commerce and trade between the two countries has developed steadily in recent years. Bilateral trade amounted to 1.97 billion US dollars in 2007, increasing 16.1 percent over the previous year, according to Chinese statistics.

Committed investments by Chinese companies in North Korea reached 445 million dollars by May this year.

The deepening of commercial and trade ties has boosted the development of both countries and brought real benefits to the two peoples.

Exchange and cooperation in the fields of culture, sports, education, and technology have also intensified, with many programs carried out every year.

Moreover, Chinese TV series aired in North Korea have created a sensation throughout the country.