North Korean leader Kim Jong-un's sister Yo-jong returned to a hero's welcome from South Korea on Sunday.
The official Rodong Sinmun carried pictures on the front page every day of Kim Yo-jong talking or standing with President Moon Jae-in. It was the first time the Workers Party organ has ever published a picture of Moon.
The North Korean delegation to the Pyeongchang Winter Olympics was welcomed back by honor guards at Pyongyang Sunan International Airport on Sunday night.
They were greeted by senior party officials and military brass such as Foreign Minister Ri Yong-ho, Kim Yong-chol, the head of the United Front Department and Armed Forces Minister Pak Yong-sik.
The official [North] Korean Central News Agency said their visit to South Korea "aroused expectations at home and abroad, and provided meaningful momentum to improve inter-Korean relations and create a peaceful environment on the Korean Peninsula."
In its Sunday's edition, the Rodong Sinmun carried several pictures showing Kim Yo-jong's whole itinerary in South Korea.
But another regime mouthpiece threatened, "The inter-Korean relations will break up if the nuclear issue is brought up."
"It is benighted and spineless" for the South Korean defense and foreign chiefs "to recklessly disparage and humiliate our nuclear weapons -- the sword of the nation and the symbol of peace," the Uriminzokkiri website said.
"South Korean authorities should clearly understand that consequences undesirable for the inter-Korean relations will arise, if they irritate their dialogue partner," it added.