The nuclear test on Feb. 12 was a "self-defense" measure in reaction to the United States' ever increasing threat, a diplomat of the Democratic People's Republic of Korea (DPRK) said here on Tuesday.

Jon Yong Ryong, first secretary of the DPRK's mission in Geneva, told a public plenary of the Conference on Disarmament that it was a primary counteraction measure for self-defense and dignity of the nation, in which it had "exercised maximum self-restraint."

In response to the statements by the United States, Jon said that if the United States took a hostile approach towards the DPRK, it would render the situation complicated and this would only lead the DPRK to take successively stronger steps.

The DPRK also threatened South Korea with "final destruction" at the meeting, according to media reports.

"As the saying goes, a new-born puppy knows no fear of a tiger. South Korea's erratic behavior would only herald its final destruction," Jon was quoted as saying.

The United States said that there was nothing defensive in the carrying-out of nuclear tests in violation of international obligations and United Nations resolutions which demanded that the DPRK did not carry out additional tests, and which reiterated the determination of the UN Security Council to take action in case of future tests.