* N.Korea has no plans to use Olympics as political vehicle - KCNA

* US officials say tough new sanctions on North Korea coming

* Pence travels to South Korea on eve of Olympics

* Kim Jong Un's sister to attend Olympic opening ceremony

* Major military parade planned in North Korean capital

North Korea has no intention of meeting US officials during the Winter Olympics that start on Friday, the KCNA news agency reported, dampening hopes the Games will help resolve a tense standoff over the North's nuclear weapons programme.

US Vice President Mike Pence, who described North Korea as the world's most tyrannical regime on Wednesday, flies in to South Korea on Thursday ahead of the opening ceremony in the mountain resort of Pyeongchang, just 80 km (50 miles) from the heavily armed border withNorth Korea.

The ceremony will also be attended by a senior delegation of North Korean officials, including the younger sister of leader Kim Jong Un and the North's nominal head of state, Kim Yong Nam.

"We have never begged for dialogue with the United States and it will be the same going forward," KCNA reported on Thursday, citing Cho Yong Sam, director-general of the NorthAmerican department of North Korea's foreign ministry.

"To be clear, we have no intention of meeting with the US during our visit to South Korea", and no plans to use the Winter Olympics as a political vehicle, Cho said.

South Korea wants to use the event to re-engage with North Korea and open the way for talks to resolve one of the world's most dangerous crises, in which US President Donald Trump and Pyongyang have swapped nuclear threats.

Speaking after meeting Japanese Prime Minister Shinzo Abe in Tokyo on his way to SouthKorea, Pence said Washington would soon unveil "the toughest and most aggressive round of economic sanctions on North Korea ever".

US Treasury Secretary Steven Mnuchin said the sanctions would be unveiled "in the coming weeks" and urged all countries to fully implement existing UN sanctions and to back the US pressure campaign by expelling North Korean "financial facilitators and trade reps".

MILITARY PARADE

North Korea is set to mark the founding anniversary of its army with a large military parade in Pyongyang on Thursday, having last month changed the date of the celebration to the eve of the Olympics.

Pence will meet South Korean President Moon Jae-in in Seoul later on Thursday. On Friday, before he attends the Olympic opening ceremony, he will visit a memorial for 46 South Korean sailors killed in 2010 in the sinking of a warship that Seoul blamed on a North Korean torpedo attack.

Pence is taking the father of Otto Warmbier, an American student who died last year after being imprisoned in North Korea for 17 months.

Kim Yo Jong, the 28-year-old sister of the North Korean leader, will be sitting in the same stadium as VIP guests along with ceremonial head of state Kim Yong Nam.

She will be the first member of the Kim family to cross the border into the South. Kim Yo Jong is a propaganda official and was blacklisted last year by the US Treasury Department over alleged human rights abuses and censorship.

Japan's Abe, whose nation has been within range of North Korean missiles for decades, will also attend the ceremony, adding to seating complications for hosts South Korea.

South Korea asked the United Nations on Wednesday for an exemption to allow a UN sanctioned North Korean official, Choe Hwi, to attend the opening ceremony with Kim Yo Jong.

A group of 280 North Koreans arrived in South Korea on Wednesday to support athletes from the two sides at the Games. The group included a 229-member cheer squad, taekwondo performers, journalists and the sports minister.

Preliminary competition at the Games begins on Thursday, with events including curling and ski jumping.

Organisers have already been battling some challenges, including a stomach virus that has affected dozens of staff and a small fire near the Olympic village on Thursday that was quickly extinguished.