Kwon Jong Gun, the director general of the North Korean foreign ministry's Department of American Affairs, has expressed indignation over South Korea's joint military exercises with the U.S., North Korean state-run agency KCNA said Sunday. 

Jong Gun has said that there will be no diplomatic negotiations between North and South Korea unless the joint exercises end. Pyongyang views the exercises as being "aggressive by nature," despite the exercises being scaled back. 

"It is a miscalculation if they think that the very change of the name of the exercise can alter its aggressive nature," Kwon said. 

The statements come after North Korea tested two new missiles Saturday, while the U.S. and South Korea engaged in small-scale exercises.

On Saturday, President Donald Trump revealed the contents of a "very beautiful" letter that he had received from North Korean leader Kim Jong Un, which included an apology for recent small-scale missile launches, saying that they would cease once joint military exercises end.

Kim also expressed the willingness to meet Trump once again soon. The two leaders recently met at the end of June, with Trump being the first president to briefly meet Kim on North Korean territory.

North and South Korea are still technically at war with each other, as the Korean War ended in 1953 without a peace treaty. Traditionally, the U.S. has had a strong relationship with South Korea, but Trump has also forged a friendship with Kim. 

Trump and Kim have had talks in recent years, with the White House wanting Kim to commit to a denuclearization program in exchange for reduced western sanctions. Intelligence analysts interviewed by the Wall Street Journal have said that it is possible that North Korea could have made 6-7 nuclear weapons since Trump and Kim's first meeting in June 2018. 

Trump referred to Kim as "little rocket man" in front of the U.N. in September 2017, while Kim has described Trump as "mentally deranged."