The recent military disputes between South Korea and Japan are taking a toll on their cooperation in defense.
Now, officials in Seoul say Rear Admiral Kim Myung-soo, commander of the first fleet, has canceled a planned trip to Japan next month as part of a regular exchange program.
No reason was given for the cancellation, but it would appear to be the result of the dispute over Japanese planes conducting several low-altitude flybys near South Korean ships since last month.
South Korea has demanded an end to the flybys and has promised to respond sternly if they happen again.
On Saturday, reports said Japan was looking at canceling a planned port call in Busan by one of its ships set for April.