If it were fired at a lower angle, it would have traveled much farther than what was covered in the latest flight.

North Korea fired the new intermediate-range ballistic missile called the Pukguksong-2 on Sunday from an air base in the country's northwestern province toward waters off its east coast. The missile flew some 500 km before splashing down in the East Sea.

Rep. Lee Cheol-woo of the Liberty Korea Party said the agency's analysis showed the missile also boasted an improved capacity, adding such advancement in technologies will also make Washington more alert.

The NIS was quoted as saying by Lee that North Korea has been preparing for an intercontinental ballistic missile launch or planning its sixth nuclear test.

"(The latest launch) was aimed at marking late leader Kim Jong-il's 75th birthday. It is also intended to convey the North's warning in regards to the latest US-Japan summit meeting," Lee said.

The lawmaker also said as the missile used solid fuel that significantly reduced the launch preparation time to less than 10 minutes. This could effectively nullify the "Kill Chain" that is being designed to detect and destroy North Korean missile threats before they are launched. (Yonhap)