South Korea and China agreed to double-track a key air corridor between Incheon and Mongolia with the aim of greatly reducing flight delays in order to benefit travellers, the government said on Sunday.

The double-tracking will cover the 1,700 kilometers of the airway that is used by planes flying mostly to Mongolia, the Middle East, Russia and Europe from East Asia.

In 2016 some 150,000 planes used the route, up from 128,000 in 2014.

Aviation experts said that due to the large number of planes on the route and the need to maintain safe distance between each jet, delays in flights from Incheon International Airport have become very common. There were 1,344 flights that were delayed for more than an hour in 2016 due to congestion on the airway.

The decision to double-track the route can help 144,000 flights per year, with some 37 percent of the flights being South Korean flag carriers.

Seoul has been engaged in talks with Beijing on the issues since 2010 with the latest decision coming on the heels of a pact to double-track air routes to Southeast Asia.