The HK$141 billion three-runway system at Hong Kong airport went into operation on Thursday, with authorities hailing it as a historic moment for the city's aviation development.

Three flights - two taking off and one landing - were handled simultaneously at Chek Lap Kok in the afternoon, witnessed by top SAR and mainland officials attending a ceremony.

Guests included Chief Executive John Lee, Vice Minister of Transport Xu Chengguang and the director of Beijing's liaison office Zheng Yanxiong.

"The various airlines also need to fully enhance their services, strengthening major routes and to explore more new destinations for Hong Kong, especially to countries of the Belt and Road Initiative in order to raise industry competitiveness," Lee said.

One of Hong Kong’s largest infrastructure projects in recent years, the three-runway system involved the reclamation of 650 hectares of land to house the 3.8 kilometre-long extra runway.

The new system boosts the airport's capacity to 120 million passengers per year, on top 10 million tonnes of cargo.

Airport Authority chairman Fred Lam pledged to continue to implement the Airport City blueprint unveiled in 2019.

"It will attract travellers from all around the world, boost the flow of people and goods, and act as an engine of Hong Kong’s economic development," he said at the commissioning ceremony.

The authority said that it is now taking forward the phase two development of AsiaWorld-Expo, while a large-scale storage facility and other new projects will be completed from 2026 to 2031.