SEOUL-- South Korea's spy agency said Wednesday that it does not rule out the possibility of North Korea conducting yet another nuclear test following its latest launch of what appears to be an "upgraded" intercontinental ballistic missile (ICBM).

During its parliamentary briefing, the National Intelligence Service (NIS) also said the first long-range missile test since the two earlier tests in July appears intended to show off its capabilities to strike the U.S. mainland, voice discontent over China's enforcement of sanctions against it and strengthen internal unity.

After a 75-day lull, Pyongyang fired off the missile from the vicinity of Pyongsong, South Pyongan Province, around 3:17 a.m., Seoul's Joint Chiefs of Staff said. The missile flew 960 kilometers at an apogee of around 4,500 km. Hours later, the North claimed a successful test of a new ICBM, called the "Hwasong-15."

"We don't exclude that possibility," a senior NIS official was quoted as telling lawmakers in response to a question on the possibility of the North's seventh nuclear test following the Sept. 3 blast.

The NIS evaluated that the North's new missile is the most advanced ICBM that it has so far tested, according to Rep. Kim Byung-kee of the ruling Democratic Party.

"It appears to be an ICBM-class one, and there has evidently been progress," the NIS official said.

The agency also pointed out that it had detected signs of the provocation before the pre-dawn launch.

"Given that the North has been relisted as a state sponsor of terrorism, and that the North launched provocations 70 percent of the time when North Koreans warned of a response, it was certainly expected that the North would provoke," the official was quoted as saying.

Source: Yonhap News Agency