South Korea's spy agency said Monday that North Korea's leader is believed to have observed the recent botched launch of a ballistic missile from a submarine in the waters off the country's east coast.

The National Intelligence Service told lawmakers that North Korea test-fired the submarine-launched ballistic missile at around 2 p.m. on Saturday in waters off the east coast port city of Wonsan, but the launch was viewed as a failure as the missile's trajectory could not be tracked.

The agency said that Kim is believed to have watched the thwarted attempt to launch the missile, which is seen as a sign that Pyongyang has not yet mastered the technology.

North Korea claimed in May that it had successfully launched an SLBM, which outside analysts say was more of a test for an ejection rather than a firing.

Last time, the projectile fell after being ejected some 150 meters from the water and its path was traced by Seoul's authorities, said Joo Ho-young, head of the parliamentary intelligence committee, after being briefed by the NIS.

"This time, we assume the North failed to launch the missile as its trajectory cannot be verified at all," said Joo.

The North's firing of a SLBM falls just a little more than a week before the two Koreas plan to hold vice-ministerial talks at a joint industrial park in the North's border city of Kaesong on Dec. 11.

The NIS, meanwhile, said that the status of Jo Yong-won, a senior official in the North's ruling party, is presumed to have sharply risen in the rankings of those in power in North Korea, given the frequency of his accompanying the leader on on-site inspections.

Jo, assumed to be in his late 50s, is handling work on surveillance and censorship at the Organization and Guidance Department of the Workers' Party of Korea.

The Unification Ministry said earlier in the day that Jo recorded the second-most appearances in Kim's entourage after Hwang Pyong-so, the North's chief military official on political affairs.

"As the frequency of contact with the leader is a yardstick for gauging power in North Korea, Jo's rank is presumed to have considerably risen," Joo said. (Yonhap)