While Seoul supports the Trump administration's pressure campaign and agrees that improvement in inter-Korean relations requires progress on the nuclear issue, the USA and South Korea face a stiff challenge in reconciling their contrasting tactics of confrontation and conciliation.
"In view of the nature and scale of United States military reinforcements, they are created to make a preemptive strike against the DPRK", North Korean diplomat Ju Yong Chol told the UN-sponsored Conference on Disarmament, referring to his country's official name the Democratic People's Republic of Korea.
Vice president says he won't rule out speaking with North Korean officials while attending the Winter Olympics in South Korea.
Pence says he wants to help "make sure that North Korea doesn't use the powerful symbolism and the backdrop of the Winter Olympics to paper over the truth about their regime". The U.S. has advanced satellites closely monitoring the North's military activity.
"My message - whatever the setting, whoever is present - will be the same: And that is that North Korea must once and for all abandon its nuclear weapons program and ballistic missile ambitions", Pence said.
But South Korea welcomed the announcement, saying it was "significant that Kim had included his sister in the delegation".
On the sanctions announced, no specifics yet, but they are expected to be rolled out before the end of the Olympic Games.
According to the United Nations command, in 2017 more than 105,000 tourists visited the JSA from South Korea, while almost 30,000 visited from North Korea, which has expanded its tourist offerings in recent years.More news: North Korea Sold Weapons to Syria and Myanmar
Kim Yo-Jong, who is a senior member of the ruling Workers' Party, will be part of a high-level delegation due on Friday and led by the North Korea's ceremonial head of state, the unification ministry said.
Kim Yo-jong will be the first member of the Kim family to cross the border into South Korea.
"With regard to any interaction with the North Korean delegation, I have not requested a meeting, but we'll see what happens", Pence told reporters traveling with him on a week-long trip to Asia, including a visit to the Olympics in Pyeongchang.
"US officials including the defense secretary and the Central Intelligence Agency director repeatedly talked about DPRK nuclear and missile threat to justify their argument for a military option and a new concept of a so-called "bloody nose", a limited preemptive strike on the DPRK is under consideration within the U.S. administration", Ju said.
Pence's comments echoed those made by Secretary of State Rex Tillerson who has also suggested a willingness to engage with North Korea around the Olympics.
Pence watched Japanese troops demonstrate the simulated deployment of Japan's surface-to-air missile defense system, which would attempt to intercept a North Korean missile.
For Friday's opening ceremony, Pence is bringing as his guest the father of Otto Warmbier, an American student who died in June past year after being imprisoned in North Korea for 17 months. He urged countries "not to be lured by the charm offensive of North Korea", adding that the U.S. and Japan are "100 percent on the same page" on North Korean policy.