SEOUL - Seoul's Incheon International Airport is using boyband BTS-designed BT21 characters for promotional campaigns.

The airport described its joint project with the K-pop act as "a historic collaboration with the very best names in the world".

Eight films featuring BT21 are set to air at the airport this month.

The airport's president and chief executive Chung Il-young said "85 per cent of travellers to South Korea are from Asia, 60 per cent of whom are millennials. This project reflects the need for a marketing strategy targeting (the younger age group)".

The BT21 collection is co-produced by BTS and Line, the Japanese subsidiary of South Korea's biggest portal Naver.

The collection was launched in Seoul and New York on Dec 16 last year. An estimated 35,000 customers visited the Line Friends stores in New York's Times Square that day, reported Billboard.

All BTS members "actively participated in the process" of creation, BT21's official website declares. The eight characters represent the band and its seven members, reported The Korea Herald.

Since its launch in December, the product range has expanded to include cosmetics and clothing, with stores opening in major shopping hubs, including Hong Kong, Taiwan and Japan.