"South Korean flag carriers will be required to have more aircraft on standby as a way of reducing their number of delayed flights, the government said Thursday.

The requirement is part of government measures aimed at reducing delayed flight departures and arrivals, which, in the long run, will require construction or expansions of airports and their runways.

"The measures include an expansion of related infrastructure, such as airports and air routes, as part of mid- and long-term measures, as well as penalties for carriers with a high rate of flight delays," the Ministry of Land, Infrastructure and Transport said in a press release.

"In the short run, the government will work to improve the aircraft operation system to help reduce delays in flight connections, a main cause of delays, and require airlines to provide information on flight delays, and thus encourage them to voluntarily reduce such delays," it said.

The flight delay rate of the country's seven flag carriers has been on a steady rise, in line with a recent surge in air passenger traffic.

In 2014, South Korea's air passenger traffic jumped 11 percent on-year, greatly surpassing a 5.7 percent increase in the overall global air passenger traffic. The growth in the country's air passenger traffic again outpaced that of the world last year at 9.8 percent to 6.8 percent, according to the ministry.

With nearly 90 million air passengers moving through South Korean airports last year, the combined flight delay rate of South Korean airlines also shot up to record levels.

In 2015, the average delay rate of domestic flights operated by the seven local airlines came to 10.4 percent, meaning more than 1 in 10 flights were delayed more than 30 minutes from their scheduled departure or arrival times.

The rate for international flights, which are given a 60-minute leeway instead of 30 minutes, came to 3.2 percent.

The rates for both domestic and international flights are again climbing to new highs this year with the number of air passengers spiking 18.5 percent on-year to over 69.16 million in the first eight months of the year.

The delay rate of domestic flights came to 19.2 percent in the January-August period, with that of international flights reaching

5 percent.

The ministry cited traffic congestion in airways and runways as a main cause of delays, especially in the arrival of connection flights, which in turn causes delayed departures of their connecting flights.

Starting Oct. 30, local airlines operating domestic routes will be required to have more aircraft on standby to be injected into routes for passengers who are expected to miss their scheduled departure times due to late arrivals of earlier flights, the ministry said.

The government will also work to set up two single-direction airways, instead of the current one double-direction airways, on most congested routes, including the South Korea-China route and the Seoul-Jeju route. (Yonhap)