US VICE-PRESIDENT Mike Pence vowed yesterday to impose the “most aggressive sanctions yet” on North Korea over its nuclear weapons programme.

Mr Pence, who is on a six-day tour of Asia, spoke in Tokyo alongside Japanese Prime Minister Shinzo Abe. Tomorrow he will attend the opening ceremony of the Winter Olympics in Pyeongchang, South Korea.

The two Koreas have used the Games as an opportunity for reconciliation, with North Korea sending a large delegation.

But Mr Pence said yesterday that the US would “continue to isolate North Korea until it abandons its nuclear and ballistic missile programmes once and for all.”

"We’ll be there to cheer our athletes, but we’ll also be there to stand with our allies, and remind the world that North Korea is the most tyrannical and oppressive regime on the planet,” he said.

Mr Abe urged countries “not to be lured by the charm offensive of North Korea.”

Meanwhile, Seoul said it was consulting Washington over a North Korean request to refuel the Mangyongbong-92 ferry that brought a North Korean band to perform at the games.

Existing sanctions prohibit North Korean ships and aircraft from refuelling in other countries.