A White House official said that the United States is closely watching North Korea’s pursuit of military advancement amid hostile rhetoric against South Korea by regime leader Kim Jong-un. 

John Kirby, the National Security Council coordinator for strategic communications, made the remark on Tuesday during a press briefing when asked if there has been a change in the North’s military posture.

Refraining from discussing intelligence assessments, Kirby simply said that the U.S. is monitoring the North and remains confident that the defensive posture maintained on the Korean Peninsula is sufficient relative to the risk posed.

Asked to comment on the report on Russian President Vladimir Putin's possible trip to the North, the spokesperson noted Washington's concerns over growing military ties between Pyongyang and Moscow.

Kirby said the concern is not only that Putin benefits by obtaining ballistic missiles to use in Ukraine as well as artillery, but also the effect on peace and security in the region stemming from whatever benefit North Korea also stands to gain from the deepening ties.