South Korea needs to tread carefully when working with the North Koreans for the coming Winter Olympics and be mindful of cultural differences that can give rise to misunderstandings, said the mayor of Seoul.

Mr Park Won Soon told foreign journalists at a press briefing yesterday that the capital city will provide all the necessary support and security for North Korean groups staging performances here as part of the Feb 9-25 Olympics.

He warned, in reference to two recent incidents, that the North Koreans may not be able to understand the South's political diversity and freedom of expression.

These were the recent controversy over protesters burning a photograph of North Korean leader Kim Jong Un in front of a Pyongyang delegation visiting Seoul and the North's abrupt cancellation of a pre-Olympic joint event citing "insulting" South Korean media reports on their "sincere" efforts.

"Peace between the two Koreas is very fragile," Mr Park, 61, said.

The two-term mayor stressed the need to "take a cautious approach" when dealing with the North Koreans, even though their participation next month is a "long-awaited opportunity" to improve inter-Korean ties chilled over Pyongyang's rampant missile and nuclear tests in the past two years.

The two Koreas are technically still at war as the 1950-1953 Korean War ended in a truce.

But they have been in talks since Mr Kim, in his New Year's Day speech, offered to send a delegation to the Winter Games to be hosted by Pyeongchang.

Besides 22 athletes, the North is sending 230 cheerleaders, 140 art performers and a 30-strong taekwondo demonstration team.

Both sides have agreed to march together under one unified flag at the opening ceremony and field a joint women's ice hockey team.

Comprising 23 South and 12 North Koreans, the team started training together on Sunday. But, according to reports, they have had to overcome communication issues arising from different use of words and hockey terms. South Korea's sports authority even compiled a list of words to help the players understand one another better.

Mr Park said Seoul will continue to fight fine dust pollution and take urgent steps to improve air quality during the Games, which will draw international media attention.

While acknowledging the fierce debate sparked by the city's decision to provide free public transport on three days when the air was very bad two weeks ago, the mayor insisted there is a need to "take as many measures as possible" to ease air pollution.