The escalating Japan-South Korea trade crisis is biting deeper into airline operations with more flights to be suspended between the two countries over the next two months as South Korea's campaign to boycott anything Japanese takes its toll.

Eastar Jet (ETJ) will be the worst affected, with six routes to cease operations indefinitely starting September 18. The six are from Incheon to Saporro, Okinawa, Ibraki, and Kagoshima, and Cheingju-Osaka and Cheongju-Saporro, all operated by Boeing 737-800s, as passenger loads continue to drop.

Low-cost carrier T’Way Air (TWA), which has already suspended the Muan-Oita flight, will add Busan-Oita, Busan-Saga, and Daegu-Kumamoto starting August 15 through to September. Air Busan will suspend Daegu-Tokyo (Narita) flights.

Air Seoul, which operates 11 of its 17 international routes to Japan, is yet to determine which routes will be suspended.

According to Lee Hong-tae, an official at the Ministry of Land, Infrastructure, and Transport (MLIT), flight bookings continue to drop as the boycott spreads. “It is uncertain when the situation will improve, but I hope it will not prolong,” Lee noted.

An ETJ executive who identified himself only as Kim said the carrier was approached by a high-level local government’s transport and tourism delegation from Japan to maintain the current schedule of flights due to severe losses suffered by companies in the affected cities.

Kim said there was no way the airline could go on operating as bookings continue to be very weak, having dropped 30 percent in July and 45 percent in August with hardly any in September. The delegation had also visited Air Seoul and Jeju Air, he said.

“The Japanese had offered to cooperate in a couple of projects in a bid to win over the LCCs,” Kim pointed out, declining to reveal details.

On August 5 the Japanese government passed a bill to remove South Korea from its list of trusted partners. It is the first country to lose this position. This prompted more South Koreans to participate in the "Boycott Japan" campaign against traveling to Japan and buying its products.

On the plus side LCCs are seeing an increase in flight bookings for August to other destinations where the airlines operate: Hanoi (43 percent); Kota Kinabalu, Malaysia (40 percent); Taipei (31 percent); Shanghai (31 percent); and Bali 30 percent.