The US and South Korea stand united against North Korea's nuclear program, even as the two Koreas hold talks in conjunction with the Winter Olympics, US Vice President Mike Pence said Saturday.

Analysts say the North's Olympic diplomatic drive seeks to loosen international sanctions against it and undermine the alliance between Seoul and Washington.

Pence, speaking to reporters abord Air Force Two after attending the opening ceremony of the Games in Pyeongchang, South Korea, said that he and President Moon Jae-in "continue to stand strong" and coordinate efforts against the North.

"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 said as he flew back to the United States.

Washington calls it a campaign of "maximum pressure."

Global alarm at the rapid advance of nuclear-armed North Korea's weapons technology rose further last year when the regime tested its Hwasong-15 ballistic missile theoretically capable of hitting the mainland US, in a challenge to Washington that has threatened to "utterly destroy" the regime in the event of an attack.

President Donald Trump and the North's leader Kim Jong Un have engaged in a series of personal insults.

But as tensions rose between the North and Washington, the Games triggered a rapid reconciliation between the two Koreas, who are still technically at war.

– Summit invitation –

Moon was invited to a summit with Kim, even as the US warned against falling for Pyongyang's Olympic charm offensive.

The invitation was issued through Kim's sister, Kim Yo Jong, who was attending the Games with the North's ceremonial head of state Kim Yong Nam.

Pence did not interact with the North Koreans even though he was seated in the same box as them at Friday's opening ceremony.

Neither did Pence shake hands with Kim Yong Nam while making a brief appearance at a leaders' reception ahead of the ceremony — although Japanese Prime Minister Shinzo Abe did so.

Moon did not respond directly to the invitation from Kim Jong Un, and urged Pyongyang to actively seek an "absolutely necessary" dialogue with Washington, Moon's spokesman said.

Washington insists that Pyongyang — which is under multiple sets of United Nations Security Council sanctions — must take concrete steps toward denuclearization before any negotiations can take place.

A senior US administration official told reporters that Pence did not discuss North Korea's invitation to Moon when the two leaders watched short track speed skating together.

Although inter-Korean talks are occurring on the sidelines of the Olympics, Pence is confident that Seoul and Tokyo "are solidly with our alliance and the need to continue and intensify economic sanctions," the official said.

UN chief urges dialogue in talks with N. Korea ceremonial leader
United Nations, United States (AFP) Feb 9, 2018 – UN Secretary-General Antonio Guterres urged North Korea's ceremonial head of state Kim Yong Nam to engage in dialogue on ending the nuclear crisis during a brief exchange in South Korea, a UN spokesman said Friday.

Kim and Guterres attended a dinner ahead of the opening of the Winter Olympics in Pyeongchang.

"He did have a brief exchange with president Kim," said UN spokesman Farhan Haq.

Guterres reiterated "his expectation and hope that all parties will use dialogue to achieve the peaceful denuclearization of the Korean peninsula," he added.

Kim is leading the North Korean delegation to the Olympics that also includes Kim Yo Jong, the younger powerful sister of North Korean leader Kim Jong Un.

The UN spokesman said Guterres did not meet with Kim's sister.

The exchange with Kim however was the highest-level meeting between the UN chief and North Korea.

Guterres has met with the foreign minister and Pyongyang's ambassador to the United Nations. Kim holds the title of president of the presidium of the Supreme People's Assembly, making him technically the head of state.

The UN chief has been a strong supporter of the thaw in relations between Pyongyang and Seoul during the Olympics, which he maintains could provide the basis for a broader dialogue.

At an official lunch hosted by South Korean President Moon Jae-in, Guterres expressed his "total support" to Moon for establishing "a very important positive development in inter-Korean relations.

"We hope that these Olympic Games will open a window of opportunity to allow for a strong diplomatic engagement aiming at the peaceful denuclearization of the Korean peninsula," said Guterres.

US Ambassador Nikki Haley has dismissed North Korea's decision to attend the Olympics as a "distraction," and Vice President Mike Pence skipped the dinner on Friday.

In December, Guterres dispatched UN political chief Jeffrey Feltman to Pyongyang for talks, but the envoy came back with no commitment from North Korea to hold negotiations on the nuclear standoff.

North Korea's race to build an intercontinental ballistic missile that could hit the United States with a nuclear warhead has raised fears of a devastating conflict.

At the United Nations in September, President Donald Trump vowed to "totally destroy" North Korea if it launches an attack on the United States.

Trump's administration has been adamant that North Korea must first freeze its military programs before talks can take place.