China and North Korea are celebrating today that they have been friends for 70 years. The leaders of the two countries exchanged letters, praising each other in flowery language.

Chinese President Xi Jinping praised the “sustainable, healthy and stable” relationship between Beijing and Pyongyang, which plays an “important role in maintaining regional peace and stability.” In turn, North Korean leader Kim Jong-un sent a message to Xi, in which he spoke of “the invincible friendship” between his country and China and their common goal of “defending and glorifying” socialism.

On the personal level, the two leaders also get along well. Since March last year, Xi and Kim have met five times. North Korea was one of the first countries to recognize the People’s Republic of China after Mao declared it on October 1, 1949.