North Korea's defiant pursuit for nuclear weapons and intercontinental ballistic missiles will move it closer to the deployment of a nuclear-armed missile within five years, a senior Seoul official warned Friday, in what would be the first such assessment on the North's nuclear weapons capability.

Yun Duk-min, the president of the Korea National Diplomatic Academy affiliated with the foreign ministry, also said that, "The countdown for North Korea's deployment of nuclear-armed missiles has begun after the North's third nuclear test and the successful launch of a long-range missile.

"Unless we stop the current trend of North Korea's development of nuclear weapons, it will be possible for the North to commission its nuclear-armed missile unit within five years," Yun told a security conference hosted by the ministry.

Following its successful launch of a long-range rocket last December, North Korea has claimed it successfully carried out a nuclear test on Feb. 12, its third since 2006, with a "miniaturized" bomb.

The North's latest atomic test prompted the U.N. Security Council to further tighten existing sanctions against the North.

Still, few experts believe that North Korea has mastered a technology that could theoretically enable it to mount a nuclear warhead on a missile.

Prospects for nuclear-tipped missiles could also raise security concerns in the region and beyond, considering that the North's

Taepodong-2 long-range ballistic missile is believed to be capable of reaching as far as Alaska.

Last year, South Korea's Defense Minister Kim Kwan-jin told lawmakers that he suspects North Korea has completed development of smaller nuclear warheads that it can deliver by missiles or aircraft.

But the defense minister said his remarks were based on suspicion, not firm evidence.

In November 2010, North Korea also revealed that it was running a uranium enrichment facility, which could provide Pyongyang with a second way of building atomic bombs in addition to the existing plutonium-based program. (Yonhap News)