The Japanese government will shift the airspace controlled by the US military off Chiba Prefecture, east of Tokyo, to make room for more commercial flights.
The move will allow an additional 40,000 flights a year at Narita Airport in the prefecture.
The 4,000 square kilometers of airspace are used for training by the US military. The Cabinet decided on Friday to change the boundaries of this zone and move it south in line with an agreement with the US government.
Commercial planes will be able to use the airspace while waiting to land during peak hours at Narita Airport.
The Defense Ministry says Narita Airport will be able to handle about 340,000 flights a year after the change is implemented in mid-July.