Responding to a congratulatory message from Kim Jong-un, Chinese President Xi Jinping sent a message of thanks to the North Korean leader, according to the North’s state news agency, KCNA.

A translation of Xi’s purported message, courtesy of KCNA Watch, expressed “sincere thanks to the C.C., Workers Party of Korea and Comrade Chairman for respectively sending congratulatory messages.”

The letter was reportedly not covered in Chinese state media.

“I wish that under the new situation the Chinese side would make efforts with the DPRK side to promote the relations between the two parties and the two countries to sustainable soundness and stable development and thus make a positive contribution to providing the peoples of the two countries with more wonderful happiness and defending regional peace and stability and common prosperity,” the message continued.

The note concluded with wishes for “fresh successes in the cause of socialist construction under the leadership of the WPK headed by Chairman Kim Jong-un.”

The letter comes amid warming ties between China and a South Korean administration that has expressed desire to cool tensions with the North, and ahead of a visit to Asia by the US president.

Despite South Korea’s pivot toward closer ties with China and potenially less confrontational approach with North Korea, Trump is reportedly determined to apply pressure on the issue by stressing that the world is “running out of time” in the race to resolve the Korean nuclear crisis.