Flags of China and North Korea are seen outside the Ryugyong Korean Restaurant in Ningbo, Zhejiang province, China, in this April 12, 2016 file photo.
(Photo: REUTERS/Joseph Campbell/File Photo)

Chinese President Xi Jinping has always been a good friend of North Korean leader Kim Jong Un. To prove this connection, Xi vowed to foster a "long-term and stable" friendship with the hermit state as the two nations celebrate 70 years of diplomatic ties.

In response, Kim also extended his deep appreciation in a message to his Chinese ally, saying their "invincible friendship will be immortal" as the two countries accomplish their mission of advancing the ideals of socialism, North Korean government-run news outfit KCNA reported on Sunday.

The North Koreans were one of the first nations in the world to acknowledge the People's Republic of China (PROC) after its establishment in 1949. Since March last year, the two world leaders have met on many occasions.

According to Chinese state media Xinhua News, Xi said that his country's relations with North Korea had been an "important role" in preserving peace and security in the Asian region.

Xi was the first Chinese leader to set foot in the cloistered North in more than a decade when he made a very historic visit to the nuclear-armed country in June this year.

Kim reinstated his Xi's promise by saying the two allies would continue to defend their socialist ideals and "maintain stability and peace in the Korean peninsula and the world," KCNA reported.

China's reassurance of a strong friendship between the North comes after the country's massive display of force in commemoration of its 70th founding anniversary of a communist China.

The military parade at the Tiananmen Square in the capital city of Beijing also comes a day after North Korea and the United States resumed their nuclear discussion in Switzerland.

Unfortunately, the latest round of nuclear talks failed because the US was a huge "disappointment", North Korea said. The United Nations has imposed three sets of economic sanctions against North Korea as part of pressures to force the country to halt its nuclear weapons ambitions. However, the US said the results of their latest meeting was "good".

Meanwhile, China's business ties with North Korea have greatly improved during the last six months of this year after, the Ministry of Commerce disclosed on Tuesday.

Total trade with the North hit $1.25 billion between January and July, rising 15 percent compared to the same quarter in 2018.

China's total exports to North Korea were valued at $1.14 billion - an increase of 16 percent - while its imports were up 4 percent to $120 million.