North Korea on Sunday accused the United States of provoking confrontation on the Korean peninsula with new sanctions, while South Korean protesters tried to block North Korean officials reaching the closing ceremony of the Winter Olympics.
The Olympics in South Korea have given a boost to engagement between the two Koreas after more than a year of sharply rising tension over the North's missile tests and its sixth and largest nuclear test in defiance of UN sanctions.
But the closing days of the Games have been overshadowed by a US announcement on Friday that it was imposing its largest package of sanctions aimed at getting North Korea to give up its nuclear and missile programmes.
"Thanks to our supreme leadership's noble love for the nation and strong determination for peace, long-awaited inter-Korean dialogue and cooperation have been realized and the Olympics took place successfully by the inter-Korean collaboration," the North's KCNA news agency said, citing North Korea's ministry of foreign affairs.
"On the eve of closing of the Olympics, United States is running amok to bring another dark cloud of confrontation and war over the Korean peninsula by announcing enormous sanctions against the DPRK," the state news agency said, using the initials of the North's official name, the Democratic People's Republic of Korea.
Earlier, about 100 conservative South Korean lawmakers and activists staged a sit-in near the border with North Korea, facing off against about 2,500 South Korean police to protest against the arrival of a northern delegation led by Kim Yong Chol, an official accused of being behind a deadly 2010 attack on a South Korean warship.
The delegation took a different route, prompting the opposition Korea Liberty Party to accuse President Moon Jae-in's administration of "abuse of power and an act of treason" by re-routing the motorcade to shield it from the protest.
Moon met Kim in Pyeongchang, where the Olympics are being held, before the closing ceremony, the South Korean government said in a statement.
The North's decision to send former military intelligence chief Kim Yong Chol as delegation leader to the closing ceremony has enraged families of 46 sailors killed in the torpedo attack on their ship and threatens the mood of rapprochement that Seoul wants to create at what it calls the "Peace Games".
North Korea has denied its involvement in the sinking.
For the opening ceremony, the North sent Kim Yo Jong, the younger sister of North Korean leader Kim Jong Un.
She was the centre of a frenzy of attention, especially when she appeared at the opening ceremony and stood only a few feet from US Vice President Mike Pence. They did not speak together.
Kim Yo Jong and the North's nominal head of state were the most senior North Korean officials to visit the South in more than a decade. The North Korean leader later said he wanted to boost a "warm climate of reconciliation and dialogue".
US President Donald Trump, in announcing the new sanctions on Friday, warned of a "phase two" that could be "very, very unfortunate for the world" if the sanctions did not work.
North Korea denounced the sanctions in a statement carried on its state media and said a blockade by the United States would be considered an act of war.
China also reacted angrily to the new US measures, saying on Saturday the unilateral targeting of Chinese firms and people risked harming cooperation on North Korea.
Trump's daughter, Ivanka Trump, a senior White House adviser, met Moon on Friday as part of a weekend trip to lead the US delegation to the closing ceremony of the Winter Olympics, but no official meeting between the American and North Korean delegations was planned.
Moon won election last year promising to try to improve relations with the North.