Nuclear-armed North Korea has used a UN disarmament meeting to warn that South Korea risks "final destruction."

The comments Tuesday by a North Korean diplomat at the Geneva-based Conference on Disarmament come a week after Pyongyang conducted a third nuclear test.

"As the saying goes, a new-born puppy knows no fear of a tiger. South Korea's erratic behaviour would only herald its final destruction," North Korean diplomat Jon Yong Ryong told the meeting, Reuters reports.

South Korea called the tests a flagrant violation of UN resolutions and a threat to the entire international community.

U.S. envoy Laura E. Kennedy tweeted later that the North's comments had been "offensive."

Numerous countries including the U.S., Britain and Germany, condemned North Korea's latest test at the meeting and urged North Korea to abide by UN resolutions barring it from testing nuclear weapons or missiles.

Even China, a longtime provider of food, fuel and other support, had warned North Korea not to conduct a third nuclear test.

"The North Korean regime's reckless disregard for the global will is again on display," Canadian Foreign Affairs Minister John Baird said after the latest nuclear test.

"What makes such actions even more unconscionable is the fact that the North Korean people starve and are denied their basic human dignity while the Pyongyang regime squanders limited resources."

With files from CBC News