North Korea says it is closely monitoring South Korea-U.S. joint drills ongoing in the East Sea while defending its recent missile launches as self-defense against U.S. threats.

A spokesperson for the North's defense ministry said Saturday that the exercise is a "bluff" as Seoul and Washington want to send a warning to Pyongyang's justified response to their joint drills. But the regime added that it is keeping tabs on the concerning development.

The nuclear-powered aircraft carrier, the USS Ronald Reagan, returned to the East Sea in the wake of North Korea's latest saber-rattling and is holding more drills with South Korea in addition to last week's exercise.

Meanwhile, the North has also lashed out against the International Civil Aviation Organization which adopted a resolution condemning the regime's missile tests as a violation of UN Security Council resolutions.

The North's National Aviation Administration issued a statement arguing the missile tests are ordinary and planned self-defense measures against direct military threats from the U.S.

It claimed the tests did not pose any threat or harm to neighboring countries and blamed the U.S. for forcing the organization to adopt such a resolution.

The UN agency has denounced the North's ballistic missile launches over or near international air routes without prior notice as a serious threat to the safety of civil aviation.

[Photo : YONHAP News]