Beijing sees the installation of the US Terminal High Altitude Area Defense battery on South Korean soil as a security threat, although Seoul insists the missile defense system aimed at countering North Korea's missile threat.

The number of foreign flights which have flown to Gimhae International Airport dropped to 256 in June from 392 in April.

Numbers stood at 442 in April last year, according to the data by the Korea Airports Corp. 

Cheongju International Airport also witnessed a decline in the number of foreign flights to 124 in March from 198 in January with the number of passengers also falling to 15,164 from 28,424.

The numbers further shrank to 46 flights and 4,099 passengers in April before rising slightly to 64 flights and 5,313 passengers in May.

Muan International Airport in the country's southwest was hit hardest.

The airport has seen the cancellation of all charter flights to and from Chinese cities so far this year, although 6,727 passengers used the airport to take 496 flights to and from Chinese cities.

Asiana Airlines, South Korea's second-largest full-service carrier, suspended the operation of twice weekly flights to Beijing from Muan between March 26 and April 23.

China Eastern Airlines also stopped flying once weekly flights from Shanghai to Muan between May and October, citing a lack of passengers.

"It will take at least several months for us to recover from the reduced flights as we need time to attract passengers even after China lifts the sanctions," an industry source said. (Yonhap)