China is planning to close the airspace north of Taiwan from April 16 to 18, four sources with knowledge of the matter said, a move that could disrupt flights around the region.
China and Taiwan's foreign ministries did not immediately respond to requests for comment.
Four officials outside China, speaking to Reuters on condition of anonymity due to the sensitivity of the matter, said the ban would disrupt Taiwan's northern flight information region (FIR) and that they were not aware of the reason for the restrictions.
It comes as China rounds off several days of military training around self-ruled Taiwan, a response to Taiwan President Tsai Ing-wen's recent meeting with U.S. House Speaker Kevin McCarthy in California which infuriated Beijing.
One senior official with direct knowledge of the matter said the flight ban would affect 60%-70% of flights going between Northeast Asia and Southeast Asia, as well as flights between Taiwan and South Korea, Japan and North America.
According to OPSGROUP, an aviation industry cooperative which advises on flight risks, previous restrictions imposed during Chinese military drills last August resulted in significant disruptions to flights in the region, with some pilots forced to carry extra fuel.
(Reporting by Yimou Lee in Taipei and Sakura Murakami and Tim Kelly in Tokyo; Editing by Jacqueline Wong and Christian Schmollinger)
