By Alex Jensen

SEOUL

South Korea on Tuesday insisted that Seoul and the United States remain committed to their joint objective of a “complete nuclear dismantlement [of North Korea] in a peaceful manner."

South Korea’s Foreign Ministry’s statement quoted by Yonhap News Agency came hours after the North's Foreign Minister Ri Yong-ho accused U.S. President Donald Trump of declaring war with his Saturday tweet asserting that Pyongyang's regime "won't be around much longer."

"As long as the U.S. has declared war, from now on, even if U.S. strategic bombers don't fly into our airspace, we will hold all the rights to self-defense, including the right to shoot them down at a time of our discretion. We will see then who lasts longer," Ri told reporters in New York, where he was attending the United Nations General Assembly.

White House press secretary Sarah Sanders also dismissed Pyongyang's claim as "absurd."

U.S. Air Force B-1B Lancer bombers and F-15C fighter jets did fly closer to the North on Saturday than ever before in the 21st century.

On a related note, Seoul's National Intelligence Service (NIS) revealed Tuesday that the American fly-by appeared to have taken North Korea by surprise as the reclusive state showed no sign of an immediate response.

Parliamentary intelligence committee chief Lee Cheol-woo revealed to local media that lawmakers were told by the NIS that "as the flight was close to midnight, the North might have not anticipated it at all, or the North might have been unable to take action as its radar or other systems could not clearly detect it."

He added that North Korea seems to be doing all it can to avoid provoking a war along the inter-Korean border -- the NIS understands that Pyongyang has directed its armed forces to "report first before taking any military measures."