The commander of the South Korean Navy's First Fleet has called off a planned trip to Japan next month amid strained bilateral ties over alleged low-altitude flybys by Japanese patrol planes, the South's Yonhap news agency has reported.

Rear Adm. Kim Myung-soo was slated to visit the Maritime Self-Defense Force's Maizuru District facility in Maizuru, Kyoto Prefecture, in February under a bilateral exchange program in which senior officers visit each other's countries in alternate years.

"It is our turn to send our naval officer to Japan," a military official was quoted Sunday as saying on condition of anonymity. "But we have notified Japan of our decision not to send any this year."

On Saturday, South Korean Defense Minister Jeong Kyeong-doo denounced the recent alleged flybys near South Korean naval vessels, calling them a "serious provocation."

South Korea alleges that Japanese patrol planes deliberately flew at low altitudes near South Korean naval vessels three times this month.

The accusations follow a dispute between the two sides over whether a South Korean Navy destroyer locked its fire-control radar on a Japanese patrol aircraft in the Sea of Japan last month.

Also Saturday, a Japanese government source said that the Defense Ministry plans to cancel a port call by a helicopter carrier in South Korea this spring.

The MSDF had planned to dispatch several vessels — including the Izumo helicopter carrier — to Busan to take part in a joint exercise that was set to be held when defense ministers from the Association of Southeast Asian Nations and its regional partners meet in the South Korean port city, the source said.