North Korea had earlier in the day launched several short-range missiles into the seas off its coast, Japanese and South Korean media reported earlier. Some reports had speculated that the test firings were timed to coincide with South Korea's launching of a new destroyer equipped with a high-tech Aegis radar system.
"I see this as part of a regular annual exercise," the intelligence official was quoted by Yonhap as saying.
Yonhap also cited an unidentified Unification Ministry official as saying the tests would not strain ties.
"I understand that North Korea test-fires short range missiles every year. It's not likely to have any immediate effect on inter-Korean relations," the official was quoted as saying.