“We cannot have a war on the Korean Peninsula ever again,” he said during a presidential office meeting, followed by talks with U.S. Joint Chiefs of Staff, Gen. Joseph Dunford.

U.S. President Donald Trump created global shockwaves last week when he said North Korea would face “fire and fury” if it threatened his country – although Pyongyang responded by elaborating on a plan to fire ballistic missiles into waters near U.S. forces stationed in Guam.

“I urge North Korea to immediately stop all provocations and threats, and stop making the situation worse,” Moon said during a weekly meeting with top aides, according to local news agency Yonhap.

Moon, who assumed office this May, added he is “confident the U.S. too will react calmly and responsibly to the ongoing situation”.

During talks with Dunford, Moon reiterated that he wants cooperation with North Korea, but added that security conditions on the peninsula constitute “a more serious, real and urgent threat than ever created by the advancement in North Korea's nuclear and missile technologies”.

Separately, Seoul’s Defense Minister Song Young-moo played down chances of the North actually firing any missiles close to Guam. In a parliamentary defense committee report, Song described the likelihood extremely low.