South Korea said on Tuesday that North Korea had proposed a new air route through the two countries, as relations between the neighbours thaw after a breakthrough meeting of their leaders last month.
At the historic summit, North Korean leader Kim Jong Un agreed to end military hostilities against the South in every area, including airspace, and revitalize exchanges with South Korea, which is technically at war with Pyongyang.
United Nations aviation agency directors will visit North Korea this week to discuss an earlier request by Pyongyang to open new air routes to South Korea, the organization said on Friday.
Japanese broadcaster NHK said two agency officials arrived at the Beijing airport on Monday en route to Pyongyang, with one of them saying they would discuss flight safety with North Korea.
In October, the agency condemned North Korea over its continued launch of ballistic missiles that threaten the safety of international civil aviation.
"We are aware that what North Korea has proposed is opening an international air route that will link Pyongyang's FIR and Incheon's FIR to a third country, not a direct flight route between Pyongyang and Incheon," South Korean foreign ministry spokesman Noh Kyu-duk told a regular briefing.
He was using abbreviations to refer to the flight information regions of each country.
If established, the new route would be an air traffic highway for any flight passing through the two countries' airspace, a South Korean government official with direct knowledge of the matter said.
South Korea is reviewing the North's request and nothing has been decided yet, the official added.
Countries such as Britain, France, Germany and the United States have advised airlines not to fly in North Korean airspace because unannounced missile launches pose threats to commercial jets.