North Korea's state media reported that the country conducted a test-firing of a Hwasong-17 intercontinental ballistic missile (ICBM) on March 24, as seen in this Pyeongyang-distributed photo. Yonhap

North Korea's intercontinental ballistic missile (ICBM) launched last week is assessed to be the same type it test-fired in 2017, Seoul's defense ministry told lawmakers here Tuesday, formally dismissing Pyongyang's claim that it was a brand-new one.

In a briefing to the National Assembly, the ministry said the ICBM in question is more similar to the Hwasong-15 missile than the newest Hwasong-17. It cited an analysis of the missile's flight characteristics and footage released by the North's state media.

The North has claimed success in launching the Hwasong-17 ― an ICBM dubbed a "monster" for its size. The new missile is known to have a range of around 15,000 kilometers, about 2,000 km longer than the Hwasong-15.

"Although the projectile fired on March 24 looks like the Hwasong-17 due to the increase in its top altitude and flight time, our assessment is that it is more similar to the Hwasong-15 than the Hwasong-17," the ministry said.

The ministry provided evidence suggesting the North disguised the latest launch as that of the newest missile.

It said that directions of shadows seen in the North's footage of Thursday's launch indicated the footage was taken in the morning though the actual launch took place in the afternoon.

The ministry also pointed out that the North's photos showed the missile test was conducted under clear weather though it was mostly cloudy at the launch site in Pyongyang at the time of the test.

In addition, the ministry said that it would have been difficult to carry out a successful new ICBM test following a botched test eight days earlier. The South Korean military presumes the North's failed projectile launch on March 16 involved the Hwasong-17.

Commenting on the North's intentions behind the launch, the ministry said that the North needed to deliver a "message of success" after citizens in Pyongyang witnessed an earlier failure in firing the Hwasong-17.

The North also appears to have sought to show progress in its ICBM capabilities, secure status as a military power and raise its leverage in future peace negotiations, the ministry said.

The Hwasong-17 was fired from Sunan International Airport in Pyongyang and exploded in midair over the capital.

An opposition lawmaker who attended the session said debris of the missile fell in Pyongyang and caused civilian damages.

"(The missile) exploded several kilometers above Pyongyang, so it was visible to the naked eye, and debris fell like rain over Pyongyang. Human casualties have not been confirmed, but civilian damage occurred," Ha Tae-keung of the main opposition People Power Party told reporters citing the ministry.

The firing of the Hwasong-15 was aimed at assuaging public discontent following the incident, he added.

Meanwhile, the ministry reportedly told a closed-door parliamentary session that Seoul is considering "strong" steps to take in the event of another North Korean ICBM launch, including the deployment of U.S. strategic military assets. (Yonhap)