A spokesperson for the U.S. Secretary of Defense said on Thursday that the U.S. is mindful of North Korea's desire to advance its military capabilities and will maintain the readiness posture it needs on the Korean Peninsula.

Pentagon press secretary John Kirby said in a press briefing that the U.S. remains committed to maintaining the readiness of American troops in South Korea through military exercises. 

Highlighting the importance of troop readiness, Kirby said that the U.S. recognizes the value of training and exercises to keep forces ready, and in no place is that more important than on the Korean Peninsula. 

Regarding cancelled and reduced combined military exercises during the Trump administration, the Pentagon official said the allies were still able to exercise and train at a level that keeps readiness capability intact.  

Asked about the North's development of a submarine-launched ballistic missile, Kirby said the U.S. is certainly mindful of Pyongyang's desire to advance its military capabilities and it knows exactly what those military capabilities are designed to do.