North Korea has reported that its leader Kim Jong Un and Chinese President Xi Jinping sent telegrams to each other to celebrate 75 years of diplomatic ties.

North Korea's ruling Workers' Party newspaper, Rodong Sinmun, carried the messages from the two leaders on Sunday, the day of the anniversary.

Kim's message said developing friendly relations serves the fundamental interests of the two countries. It stressed that North Korea will steadily strive to consolidate and develop friendly relations as required in the new era.

Xi said in his message that he has maintained close communications with Kim through several meetings. He expressed his hope to mark the 75th anniversary by announcing that China is willing to strengthen strategic communications and deepen friendly exchanges and cooperation with North Korea.

The report comes amid international speculation that the two countries' relations are receding, as few exchanges have been seen recently.

South Korea's National Intelligence Service reported in its analysis at the parliament in September that China-North Korea relations have been deteriorating significantly. It noted that recently China is reluctant to accept North Korean workers.