North Korean and Chinese leaders Kim Jong-un and Xi Jinping pledged to strengthen cooperation between their two countries in the face of hostile foreign powers.

The two presidents exchanged messages on the occasion of the 60th anniversary of the signing of the "Treaty of Friendship, Cooperation and Mutual Assistance" between the two countries, according to the official North Korean News Agency, "Yonhap.”

The exchange came about 10 days after Kim Jong-un sent a congratulatory letter to Jinping on the centenary of the Chinese Communist Party, in which he vowed to advance relations with China to a new strategic point.

“Despite the unprecedentedly complicated international situation in recent years, the comradely trust and military friendship between the DPRK and China got stronger day by day,” Yonhap quoted the North Korean president as saying.

Kim added that this friendship "gained momentum and comprehensively developed to a higher stage in all fields." 

For his part, the Chinese president pledged to "push cooperation with North Korea to a new stage." He stressed that the friendship treaty laid "important political and legal foundations for strengthening the military friendship between the two countries," expressing his hope to strengthen his "strategic liaisons" with his North Korean counterpart.

At a time when US President Joe Biden did not show any intention to ease the sanctions imposed on North Korea over its nuclear program, a South Korean newspaper revealed earlier this month an exchange of messages between the North Korean leader and South Korean President Moon Jae-in, prior to the latter's meeting with President Biden.

About a month ago, the North Korean leader declared a state of alert to face the "rapid changes on the Korean Peninsula."