A ray of light shone and a bell rang out to pronounce the start of the Pyeongchang Winter Olympics opening ceremony on Friday.

All eyes settled on the rival Koreas, who marched together under a "Korean Unification" flag a day after the North staged a military parade to celebrate the 70th anniversary of the founding of the Korean People's Army.

"This is the moment that we have all been waiting for: the first Olympic Games on snow and ice in the Republic of Korea," said International Olympic Committee President Thomas Bach. "This will be the competition of your life. Over the next days, the world will be looking to you for inspiration," he said.

It was the first time the Koreas marched together at an Olympic opening ceremony since the 2006 Turin Games.

North Korean Leader Kim Jong Un's younger sister, Kim Yo Jong, was among the high-level delegation attending the opening ceremony, along with the North's ceremonial leader Kim Yong Nam, both putting a face to the heavy political tensions looming over the winter sports festival.

Others dignitaries in attendance included Japanese Prime Minister Shinzo Abe and U.S. Vice President Mike Pence.

The march under the unified Korean flag was the outcome of a landmark deal between the two rivals following a year of growing concerns over the North's nuclear weapons ambitions. The North has sent 22 athletes, more than half of whom are playing for the unified Korean women's ice hockey team.

"A great example of this unifying power is the joint march here tonight of the two teams from the National Olympic Committees of the Republic of Korea and the Democratic People's Republic of Korea. We thank you," Bach said. "United in our diversity, we are stronger than all the forces that want to divide us."

Those in attendance at the open-air Pyeongchang Olympic Stadium had to brace for the elements and were provided with windbreakers, lap blankets and even heated seat cushions for the sub-zero temperatures in the mountain town of Hoenggye.

The Olympic flame, which traveled to all corners of South Korea over the past 101 days, was carried to the cauldron, which resembled a full moon. Retired Olympic figure skating champion Kim Yu Na was the final person to carry the flame. Kim, who skated atop a platform, lit the cauldron.

The protagonists for the opening extravaganza were five child actors from Gangwon Province, representing the five Olympic rings and the five elements -- fire, water, wood, metal and earth -- on a journey that connected past, present and future.

In the show, the children traveled to the past and the future, learning about the history and culture of their land as they sought answers to questions of peace envisioned by Koreans.

In the portion called the "Arirang: The River of Time" Kim Nam Gi sung the soulful "Jeongseon Arirang" folk song. The time travel ended with the children returning to the present, holding candles. When the stage was filled with light, five children released a dove into the sky in a prayer for world peace.

Approximately 2,500 athletes from over 90 countries and territories are taking part in the Feb. 9-25 Games, competing in 102 medal events across seven sports and 15 disciplines.

Four new events -- big air snowboarding, mass-start speed skating, team Alpine skiing and mixed doubles curling -- are on the 2018 Winter Olympic program.

Team Japan has been tipped to have its largest medal haul ever at a Winter Olympics. Netherlands-based sports statistics firm Gracenote projects a record 15 medals for Japan, nearly double the outcome from Sochi, where the athletes brought home one gold, four silver and three bronze medals.

Japan's medal hopefuls include men's figure skating golden boy Yuzuru Hanyu. Figure skaters Shoma Uno and Satoko Miyahara are good chances to take lesser medals.

Japanese sprint queen and team captain Nao Kodaira, who skipped the ceremony due to the extreme cold, leads the charge for gold in speed skating. Veteran ski jumper Noriaki Kasai, who is appearing in a record eighth games, acted as the Japanese team's flagbearer.

"Last time I was captain, and this time I am very happy to be given an important role again as flagbearer," Kasai said ahead of the ceremony. "I plan to wave the flag, cheering on the athletes on the Japanese team so they can all perform their best."

A strong showing by Japanese athletes in Pyeongchang could also go a long way to making a reality Sapporo's bid to host the 2026 Winter Games.

It is the third Winter Olympics being held in Asia after the 1972 Sapporo Games and the 1998 Nagano Games. South Korea, which hosted the 1988 Seoul Olympics, is staging the cold weather games for the first time.

Six NOCs -- Ecuador, Eritrea, Kosovo, Malaysia, Nigeria and Singapore -- are participating in a Winter Games for the first time.

On the same day, the Court of Arbitration upheld a doping ban of 47 Russian athletes, keeping them out of the Pyeongchang Games.

The IOC is allowing athletes who have proven their innocence to compete individually under the OAR -- Olympic Athletes from Russia -- moniker while banning the display of the Russian flag or the playing of the national anthem.