South Korea's military on Friday saw a possibility for the Democratic People's Republic of Korea (DPRK) to test-launch another Musudan ballistic missile after repeated failures in recent weeks.

Defense Ministry spokesman Moon Sang-Kyun told a press briefing that possibility for an additional launch of Musudan missile cannot be ruled out in consideration of the DPRK's push for the launches even after repeated failures.

The DPRK launched two Musudan missiles on Thursday after conducting its first test-firing of the missile from a mobile launcher on April 15.

The three launches were believed to have failed as the missiles exploded in mid-air or crashed in waters several seconds after liftoff.

Before this month's launches, the DPRK had never test-fired the mobile Musudan ballistic missile, known to be capable of striking part of the U.S. territory such as Guam and the outer reaches of Alaska, since the missiles were deployed in 2007.

The missile is seen as especially threatening as it is fired from a mobile launcher, making it hard to detect and track in times of military conflicts. It can also carry a nuclear warhead.

Concerns spread here about the DPRK's fifth nuclear test and ballistic missile launches, aimed at proving its claim that it possesses technology of nuclear-tipped ballistic missiles, ahead of a historic Workers' Party of Korea (WPK) convention next week.

The DPRK announced its plan to hold the 7th WPK congress on May 6, which would be the first since 1980.

South Korea's military has kept close tabs on the DPRK forces due to a high possibility of Pyongyang's fifth nuclear test in the near future, Moon said, noting that the DPRK was seen as having completed preparation for nuclear detonation.