North Korean leader Kim Jong Un has offered his personal condolences to “compatriots” in the South over an ongoing outbreak of the novel coronavirus (COVID-19), in a letter to President Moon Jae-in delivered on Wednesday.

The letter, made public by South Korea’s Blue House at a briefing to press on Thursday, notably, saw Kim praise his “unwavering friendship and trust” in his Southern counterpart, despite over a year of inter-Korean acrimony.

“Chairman Kim conveyed a message of condolences to our citizens who are fighting the coronavirus,” Yoon Do-han, senior secretary for public communication told journalists.

“He said that he believes that they will overcome it for sure. He also said that he will wish that the precious health of the compatriots of the South will be sustained,” he continued, adding that Kim had also “frankly opined on the current situation on the Korean Peninsula.”

“Chairman Kim conveyed his feelings that he is worried about President Moon’s health,” Yoon said. “He said that he will quietly cheer for President Moon to overcome COVID-19.”

President Moon has responded to the letter, Yoon said, thanking the North Korean leader for his note, which represents the first direct communication between the leaders of the two Koreas since October last year.

It’s not immediately clear how the letter was delivered, with officials simply saying it had been received through a “communication channel” between the two and stressing it would be “hard for us to reveal the exact content.”

Despite this, Yoon stressed the reconciliatory tone of Wednesday’s note, while adding there had been no mention of recent South Korean proposals for the two Koreas to cooperate in the field of public health.

“In the letter from Chairman Kim Jong Un there were references to [Kim’s] unwavering friendship and trust towards President Moon,” he said.

“It is important to sustain such mutual relations as the South and the North are continuously pursuing peace… we understand that the exchange of letters is being done in that sense.”

The letter this week came amid a continued rise in reported cases of the novel coronavirus in South Korea, with close to 6000 infections having been detected as of Thursday afternoon.

North Korea has continued to claim that there are zero confirmed cases of COVID-19 in its territory, despite an increasing number of people reported to be under quarantine in South Phyongan, North Phyongan, and Kangwon Provinces.

It also comes in stark contrast with a statement by Kim Jong Un’s sister, top official Kim Yo Jong, on Tuesday, in which she derided South Korea’s “foolish” Blue House for recent criticism of a North Korean military drill.