A blacklisted North Korean general arrived in the South today for the Winter Olympics closing ceremony, which will also be attended by US President Donald Trump's daughter Ivanka.

The visit by Kim Yong Chol, who led an eight-member high-level delegation that crossed the Demilitarized Zone in the morning, is the final piece of the Games-led diplomacy that has dominated headlines from Pyeongchang.

The nuclear-armed North has gone on a charm offensive over the Games, sending athletes, cheerleaders and performers and with leader Kim Jong Un's sister Kim Yo Jong attending the opening ceremony.

Analysts say it is seeking to loosen the sanctions imposed against it over its banned nuclear and missile programmes, and trying to weaken the alliance between Seoul and Washington.

But Kim Yo Jong had no interaction with US Vice President Mike Pence at the opening ceremony, even though they were just a few seats apart in the same VIP area. According to the US, a planned meeting between the delegations from Washington and Pyongyang the following day was cancelled at short notice by the North Koreans.

South Korean President Moon Jae-in -- who has long pushed for engagement with the North to bring it to the negotiating table -- also did not immediately accept an invitation passed on by Kim Yo Jong from her brother to a summit in Pyongyang, saying the right conditions must be created.

Washington, which describes its approach to Pyongyang as "maximum pressure and engagement", announced a series of new sanctions on Friday.

Pence also condemned Kim Yo Jong as part of an "evil family clique" and "murderous regime", prompting a denunciation from Pyongyang on Sunday -- which said it would not talk to the Trump administration for "even 100 years or 200 years".

Overnight protest

Kim Yong Chol's delegation was greeted by Seoul's vice unification minister Chun Hae-sung.

Kim, wearing a long dark coat, was later seen checking into the Walkerhill luxury hotel in Seoul with other delegates and leaving a few hours later amid heavy security involving hundreds of police officers.

Kim's nomination as the leader of the group is controversial in the South, where he is widely blamed for a spate of attacks including the torpedoing of Seoul's Cheonan warship in 2010 with the loss of 46 lives. Pyongyang denies responsibility.

Conservative lawmakers staged an overnight protest near the border with the North, joined by hundreds of other activists.

The protesters waved banners including "Arrest Kim Yong Chol!" and "Kim Yong Chol should kneel in front of the victims' families and apologise!"

Kim is blacklisted under Seoul's unilateral sanctions against the North, meaning he is subject to an assets freeze.

'Crazy remarks'

Officials from both Seoul and Washington say there will be no meeting between Kim Yong Chol and Ivanka Trump -- who is travelling with Korea specialists from the US administration and White House spokeswoman Sarah Sanders.

But the North's delegation includes Choe Kang Il, the deputy director general for North American affairs at the North's foreign ministry, suggesting Pyongyang may be open for talks.

On Friday the US Treasury blacklisted 28 ships, 27 companies and one person, imposing an asset freeze and barring US citizens from dealing with them, in what Donald Trump described as the "heaviest sanctions ever" levied on Pyongyang.

The UN Security Council has already banned North Korean exports of coal -- a key foreign exchange earner -- iron ore, seafood and textiles, and restricted its oil imports.

Washington is also seeking to have the United Nations ban 33 vessels from ports worldwide and blacklist 27 shipping businesses for helping North Korea circumvent sanctions.

Kim Yo Jong's trip at the start of the Games -- the first visit to the South by a member of the North's ruling dynasty since the Korean War ended in 1953 -- made global headlines.

But Pence told an audience of thousands at the Conservative Political Action Conference: "The sister of Kim Jong Un is a central pillar of the most tyrannical and oppressive regime on the planet, an evil family clique that brutalises, subjugates, starves and imprisons its 25 million people."

Pyongyang denounced his comments Sunday, with the official Korean Central News Agency carrying a statement from the North's Korea Asia-Pacific Peace Committee saying Pence would discover "what quagmire his crazy remarks threw the US and himself into".

Trump, it said, should know that the North would "have no dealings with those viciously slandering the dignity of our supreme leadership and government".

"We will never have face-to-face talks with them even after 100 years or 200 years."