North Korea appears to have yet to harness a missile technology for "atmospheric re-entry," which is vital for developing an intercontinental ballistic missile (ICBM), South Korea's military said on Monday.

The statement comes following Pyongyang's announcement that it successfully conducted a newly developed mid-to-long range missile test over the weekend. The ballistic missile, named Hwasong-12, reportedly flew 787 kilometers after it reached a maximum height of 2,111.5 kilometers.

North Korea's claim is believed to be true based on the data collected by Seoul, Washington, and Tokyo, a spokesperson from the South's Joint Chiefs of Staff (JCS) said, according to Yonhap News. But when asked if the missile could soar above the Earth and re-enter, the official said, "We believe chances [of it] are low."

Meanwhile, Reuters said that the recent launch indicates a significant advancement in North Korea's drive for an ICBM. The launch, supervised by leader Kim Jong Un, aims to assess the missile's ability to carry a "large scale heavy nuclear warhead."

Kim has earlier accused Washington of "browbeating" countries without nukes and told the US not to misjudge the reality that its mainland is within North's "sighting range for strike," Pyongyang's official KCNA news agency reported.

But US military's Pacific Command said that the kind of missile fired by the North was "not consistent" with an ICBM, while South Korea downplayed North's technical development claim on atmospheric re-entry.

The alleged ICBM tested by North landed in the sea near Russia on Sunday in a launch that Washington described as a message to Seoul.

Pyongyang has been working to produce a nuclear-tipped missile that is capable of reaching the US, which is about 8,000 kilometers away. However, the country is banned from engaging in any nuclear and missile development under the United Nations resolutions. Despite that, the North has so far carried out five nuclear tests and a string of missile launches since the start of 2016.