SEOUL - The new passenger terminal at South Korea's Incheon International Airport will be unveiled to the public for the first time next week ahead of the official start of its operations, its operator has said.

The Incheon International Airport Corp. (IIAC) plans to hold a pre-opening event for the 384,336 sq m second terminal built on Yeongjongdo Island, 60km west of Seoul, on Jan 12.

It has spent 4.9 trillion won (S$6.12 billion) on the massive building project.

The five-storey new terminal will formally begin operations on Jan 18, reported local media.

A Seoul-bound Korean Air flight from New York is slated to be the first to make use of the facilities at the new terminal after landing at South Korea's main air passenger hub at 5.15am on that day, according to Yonhap news agency.

Another Korean Air plane en route to Manila on the same day will be the first plane to take off from the terminal.

The new terminal, designed largely to enhance user convenience, boasts features such as 63 self-check-in kiosks and 24 full-body scanners.

It can handle around 18 million passengers per year, enabling Incheon airport to process 72 million passengers and five million tons of cargo every year.

The roof of the new terminal will be fitted with solar photovoltaic panels to reduce energy consumption, according to website Airport-technology.com.

The new terminal will support South Korean flag carrier Korean Air, as well as planes operated by KLM, Air France and Delta.

The second terminal will also handle flights carrying athletes and sports officials arriving in the country for the 2018 Pyeongchang Winter Olympics that kicks off on Feb 9.

In September 2013, the airport broke ground on a US$2.5-billion project to construct a second terminal as part of a US$4.5-billion construction package to address growing passenger demand.

Built to replace Gimpo International Airport, Incheon officially opened in 2001 and has since climbed up the ranks to become one of the world's foremost air hubs.

The Incheon airport, South Korea's largest, won the world's best airport award for a record 12th consecutive year in 2017.

It scored 4.99 points out of five, winning the title given by the annual Airport Service Quality Award event presented by Airports Council International (ACI).

The award, given by the ACI every year since 2006, was based on approximately 550,000 passenger surveys sent to 268 airports worldwide.

The airport was also named the best large airport (with at least 40 million passengers annually), the best airport in Asia-Pacific and the best large-scale airport in Asia-Pacific.

Singapore's Changi Airport came in joint-second place - tied with Delhi Airport and Mumbai Airport - for the best airport by size award, in the category for airports with more than 40 million passengers a year.

The third place went to Beijing Airport.