"There is no daylight between the United States, the Republic of Korea and Japan on the need to continue to isolate North Korea economically and diplomatically until they abandon their nuclear and ballistic missile program," Pence told reporters during a flight to the United States following his visit to South Korea, where the Olympic games are being held.

A senior administration official aboard Pence's airplane also told reporters that South Korea and Japan "are solidly with our alliance and the need to continue and intensify economic sanctions."

Last month, a White House official told reporters Pence would attend the Winter Olympics opening to cheer American athletes and to counter any North Korean effort to "hijack" the games with a propaganda campaign.

South and North Koreans marched together under a unified flag at the games' opening ceremony. International Olympic Committee President Thomas Bach called it "a very emotional moment," one that gave him "goosebumps."

President Donald Trump's administration has taken a hard line on North Korea's nuclear and ballistic missile program, saying there is no room for negotiations unless Pyongyang abandons it.

The official said Pence and South Korean President Moon Jae-in, while watching speed skating together on Saturday night, discussed intensifying sanctions.

The official said Pence and Moon did not discuss the North Koreans' invitation to Moon for a summit in Pyongyang, which would set the stage for the first meeting of Korean leaders in 10 years.

Pence did say, however, that Moon shared with him details of his meeting with North Korean leaders, without elaborating.

On his way to Asia earlier this week, the US vice president told reporters he was not seeking direct talks with North Korean officials, "but we'll see what happens."

During an Olympics reception and at the sporting event's opening ceremony, Pence was not trying to avoid North Korean officials in attendance, the senior administration official told reporters on Saturday, adding that he was trying to ignore them.

The official also noted that while Trump believes in talking, in this case, the issue is not about words but about deeds on North Korea's part.