South Korea on Tuesday rejected public calls for the country's own nuclear armament, saying it remains firmly committed to the global nonproliferation regime.

The issue has drawn attention as some politicians and analysts claim nuclear armament is the only effective deterrent against North Korea's nuclear and missile threats.

North Korea conducted its fourth nuclear test on Jan. 6 and launched a long-range rocket on Feb. 7 in the latest clear signal that it will pursue technological advances for nuclear-tipped ballistic missiles.

North Korea has claimed that it has mastered the technology to make nuclear warheads small enough to mount on missiles, though outside analysts question the country's miniaturization technology.

"As North Korea has conducted four nuclear tests and launched a long-range missile, this can be seen as coming from a sense of frustration among experts in terms of how to respond," Foreign Ministry spokesman Cho June-hyuck said during a regular press briefing.

"Our government is actively contributing to the global nonproliferation regime and working to strengthen it," he added.

"Our stance on nonproliferation is firm."

After the rocket launch, Seoul and Washington announced plans to begin talks on the possible deployment of the advanced U.S. missile defense system in South Korea.

China and Russia are strongly opposed to it, believing it could undermine their security. (Yonhap)