North Korea threatened to inflict the "final destruction" of South Korea in a United Nations conference, warning of further measures following its nuclear test earlier this month.

During a U.N. Conference on Disarmament meeting held in Geneva on Tuesday, North Korea's diplomat Jon Yong-ryong said, "South Korea's erratic behavior would only herald its final destruction," referring to the North Korean proverb, "a newborn puppy knows no fear of a tiger."

His country could take further steps in a follow-up to the Feb. 12 test of a nuclear bomb, Jon said in the gathering, without elaborating.

The North Korean diplomat claimed the country has recently taken a stern defensive-purpose measure without referring to the nuclear test, adding the U.S.'s hostile policies toward his country, if continued, could further complicate the current situation.

The diplomat's remarks came as major Western member countries like the U.S., Britain and Germany issued condemnations over the country's third nuclear test and called on the North to stop further nuclear activities.

South Korean representative Kwon Hae-ryong also made remarks urging the North to abide by United Nations resolutions and discard its nuclear ambitions in order to shift the country's focus to propping up the livelihoods of starving North Koreans.

Kwon said the North Korean diplomat reacted emotionally to condemnations from foreign countries.

Joanne Adamson, the British ambassador, called Jon's remarks "completely inappropriate" while U.S. representative Laura Kennedy said she felt they were "offensive."

Tension remains unabated following the country's detonation of what it called a miniaturized nuclear bomb in defiance of the U.N. resolutions and condemnations from the outside world.

The international community is closely watching whether the country will conduct further nuclear tests after it said it will take additional actions following the Feb. 12 test.

Experts in South Korea said the North's threat was more extreme than its previous provocative remarks, potentially reflecting the country's confidence in its nuclear capabilities and continuing its attempt to pressure Seoul.

Since first warning it would set "a sea of fire" throughout Seoul in 1994, the country has frequently repeated the threat, which experts interpreted as referring only to the North's possession of conventional weaponry including long-range artillery.

The experts said the latest remark may signal the beginning of the North's outspoken designation of South Korea as a nuclear target.

Previously, the North has explicitly mentioned its nuclear activities target the U.S., which the country regards as a main enemy.

"They would not use the term 'final destruction' if it wasn't for nuclear arms," researcher Chang Yong-seok of the Institute for Peace and Unification Studies at Seoul National University said.

  The U.N. meeting came one day after 27 foreign ministers of the European Union decided to tighten sanctions against the North for the nuclear test.

They decided to impose "more comprehensive and stronger" sanctions, which include asset freezes, travel bans as well as other financial and trading sanctions. (Yonhap News)