South Korea is urging airlines to divert their routes after North Korea warned Thursday that it could not guarantee the safety of planes that entered its airspace.
Starting Saturday at midnight local time, South Korea's Civil Aviation Safety Authority has asked airlines to stop flying near North Korea.
Two flagship carriers, Korean Air and Asiana Airlines, have already begun diverting flights.
North Korea says it cannot guarantee the safety of civilian flights because of an upcoming U.S.-South Korean military exercise.
It has warned that the exercises, which start Monday, could trigger a war.
Pyongyang's state-run media have accused the United States of preparing to invade the communist nation.
Washington and Seoul say the routine drills involving tens of thousands of troops are purely defensive.
South Korea's Unification Ministry says the threats to civilian flights are inhumane and unjustifiable and the United States has called Pyongyang's rhetoric "distinctly unhelpful."
Despite this, U.S. military officers representing the United Nations Command in South Korea resumed talks with the North Korean army Friday in an effort to reduce tensions.
The Friday talks follow a half-hour meeting on Monday, which was the first between the two sides in nearly seven years. Lower-level officers also met on Thursday.