North Korean President Kim Jong Un and departing South Korean President Moon Jae-in shared amicable letters this week, signifying a rare moment of good news for both nations as described by the state media of North Korea. 

Moon wrote Kim a letter earlier this week, according to the Korean Central News Agency of North Korea, in which he stated that despite his departure, he will continue to work toward Korean unity.

According to the news report, Kim appreciated Moon for his efforts on behalf of the country's great cause.

Kim also expressed optimism for the future, saying that their collaborative efforts have given him "hope for the future" and that "inter-Korean relationships" will strengthen.

The messages are being sent during a tough period on the Korean peninsula, as satellite footage reveals new excavation at the nuclear testing zone in Punggye-Ri, implying that Pyongyang is resuming nuclear testing despite shutting it down in 2018.

North Korea also tested a different strategic guided weaponry last weekend, done in conjunction with the birth anniversary of founder Kim Il Sung, and breached a four-year prohibition on international ballistic missile testing in late March.

More tests, according to observers, could take place around April 25, when Pyongyang commemorates the foundation of the Korean People's Army.

When President-elect Yoon Suk-yeol of the People's Power Party gets into office on May 10, Moon's five-year reign will come to an end. Presidents of South Korea are limited to a single five-year reign by the constitution.

Moon has used his tenure to interact with the North, meeting Kim three times, which is unexpected. He's also established a long-term aim of formally resolving the Korean War, which ended in 1953 with a ceasefire rather than a peace accord.

Moon's desire for peace hasn't stopped his government from pressing for further sanctions on North Korea in the wake of the round of ICBM tests recently.

He also warned in February that if nuclear or long-range missile launches started, the Korean peninsula would be plunged into a crisis. In response, North Korea has made stern threats against any military engagement by its southern neighbor, claiming that it is ready for extermination.

President-Elect Yoon has been regarded as "hawkish" in comparison to Moon, and has stated that his international relations toward the North will be centered on "total denuclearization," as well as problems of "mutual recognition" and "civil rights."