The South's Joint Chiefs of Staff had said earlier that its radar found "the traces of flight by an unidentified object" on Monday over the central portion of the Demilitarized Zone that divides the two Koreas.
News reports say South Korea launched fighter jects and helicopters in response because it believed it could be a North Korean helicopter flying across the border into South Korea. The Joint Chiefs of Staff said it can only confirm that it deployed unidentified surveillance assets to find what that object was.
The joint Chiefs of Staff said that it had confirmed that it was a flock of birds flying across the border from north to south.
South Korea's military say it has detected an "unidentified object" flying near the border with North Korea.
The South's Joint Chiefs of Staff says its radar found "the traces of flight by an unidentified object" on Monday over the central portion of the Demilitarized Zone that bisects the two Koreas. It gave no further details.
The DMZ is the world's most heavily fortified border. The two Koreas have occasionally traded exchanges of gunfire before North Korea entered talks on its nuclear program.
The meeting between Trump and Kim, their third, happened in the western portion of the DMZ.
Lee Sang-min, spokesman of South Korea's Unification Ministry, said that the Trump-Kim meeting could breathe new life into the nuclear negotiations and benefit Seoul's efforts to keep alive momentum for talks and cooperation with the North.
North Korea's state media has described Kim's meeting with Trump on Sunday at the Demilitarized Zone as "an amazing event" in the border village it notes is a symbol of the Korean Peninsula's division.