Kim Jong Un and Donald Trump
This combination of pictures created Nov. 12, 2018, shows North Korea's leader Kim Jong Un (left) during the Inter-Korean summit in the Peace House building on the southern side of the truce village of Panmunjom, April 27, 2018, and President Donald Trump during a post-election press conference in the East Room of the White House in Washington, D.C., Nov. 7, 2018. KOREA SUMMIT PRESS POOL, MANDEL NGAN/AFP/Getty Images

President Donald Trump tweeted Saturday that Kim Jong Un has apologized for conducting short-range missile tests and that he is willing to meet with Trump again soon.

The message from the North Korean leader was in a "very beautiful" letter that Trump said he received Friday.

According to Trump, Kim said that the short-range missile tests were a response to joint military exercises being conducted between the U.S. and the South Korean military. Kim has promised to finish the tests once the military exercises have ended.

South Korea said Friday that North Korea fired two short-range projectiles into the sea of Japan.

Trump's comments come amid growing criticism for his frequent defense of North Korea, a totalitarian state accused of human rights violations.

The Washington Post's headline Saturday about the joint military exercises read: "Trump again appears to take North Korea’s side against his own military, allies."

After reports surfaced in June that Kim's half brother, who was killed in a 2017 chemical-weapons attack in Malaysia, was a CIA source, Trump seemingly sided with Kim.

“I see that, and I just received a beautiful letter from Kim Jong Un,” Trump said at the time. “I think the relationship is very well but I appreciated the letter. I saw the information about the CIA with regard to his brother or half brother and I would tell him that would not happen under my auspices. I wouldn’t let that happen under my auspices. I just received a beautiful letter from Kim Jong Un.”

Another incident began in June 2017, when American college student Otto Warmbier was sent back to the U.S. from North Korea in a comatose state and then died days later. Trump would later state that he believed Kim had no knowledge of Warmbier's poor health, sparking controversy that he was supporting a foreign leader over an American citizen.

Some believe that meetings between Trump and Kim were mere photo-ops. In June, Trump became the first U.S. President to meet the leader of North Korea on North Korean territory, in a move that seemed to further legitimize North Korea as an accepted nuclear power.

The two leaders have been engaged in diplomatic talks, with Trump meeting Kim in Singapore in June 2018 and in February in Vietnam to discuss North Korean denuclearization in exchange for reduced western sanctions. A deal has yet to be reached.

North Korea is technically still at war with South Korea, as the Korean War ended in 1953 without a peace treaty.