South Korea's low-cost carriers said Monday they have delayed or reduced their flights on international routes due to the spread of the omicron variant.

Air Seoul Inc., a budget carrier unit of Asiana Airlines Inc., has delayed its planned flights to Guam from Jan. 29 to March 27.

Air Seoul has offered one flight a week, respectively, on the routes from Incheon to Qingdao and Yantai in China since the summer of 2020 to meet business travel demands.

Jeju Air Co., the country's biggest low-cost carrier, said it will continue to provide two flights a week on the Incheon-Guam route until Feb. 26. It had originally planned to provide four flights a week on the route from Jan. 27.

It also plans to operate flights on the Busan-Saipan route until Jan. 12, though the route resumed services on Dec. 29.

T'way Air Co. has provided two flights a week on the Incheon-Saipan route but decided to suspend them until Jan. 28.

South Korea has two full-service carriers -- Korean Air Lines Co. and Asiana Airlines Inc. -- and 10 LCCs, including Jin Air Co., Air Busan Co., Eastar Jet Co., Fly Gangwon, Air Premia Co. and Air Incheon Co.

Air Incheon is a cargo-focused carrier, and the nine other low-cost ones are passenger carriers. (Yonhap)