North Korea nuclear test: South would ‘decimate’ Pyongyang

South Korea has said it has a plan to annihilate the North Korean capital of Pyongyang if it shows any signs of mounting a nuclear attack, according to reports from Seoul.

A military source told the Yonhap news agency every part of Pyongyang “will be completely destroyed by ballistic missiles and high-explosives shells”. Yonhap has close ties to South Korea's government and is publicly funded.

The threat comes after the dictatorship set off its most powerful nuclear explosion to date on Friday, saying it had mastered the ability to mount a warhead on a ballistic missile and ratcheting up a challenge to rivals and the United Nations.

The United Nations security council denounced North Korea’s decision to carry out the test and said it would begin work immediately on a resolution. The US, Britain and France pushed for the 15-member body to impose new sanctions.

US President Barack Obama said after speaking by phone with the South Korean president, Park Geun-hye, and the Japanese prime minister, Shinzo Abe, on Friday that they had agreed to work with the security council and other powers to vigorously enforce existing measures and to take “additional significant steps, including new sanctions”.

“We will be working very closely in the security council and beyond to come up with the strongest possible measure against North Korea’s latest actions,” said the US special representative for North Korea policy, Sung Kim, on Sunday.

However, North Korea said threats of further sanctions against the country were “laughable”.

“The group of Obama's running around and talking about meaningless sanctions until today is highly laughable, when their 'strategic patience' policy is completely worn out and they are close to packing up to move out,” state-run KCNA news agency cited a North Korean foreign ministry spokesman as saying in a statement later on Sunday.

“As we've made clear, measures to strengthen the national nuclear power in quality and quantity will continue to protect our dignity and right to live from augmented threats of nuclear war from the United States,” KCNA added.

North Korea also demanded that the US recognise it is a “legitimate nuclear weapons state”, and defended the latest nuclear weapons test as a necessary response to what he termed a US nuclear threat.

The latest test showed North Korea’s nuclear capability was expanding fast and that the country’s leader, Kim Jong-un, was unwilling to alter course, South Korea said on Saturday.

Another KCNA report on Sunday said North Koreans were “delighted” by the nuclear test. “The enemies can no longer deny the strategic position of our country as a nuclear weapons state,” Jong Won-sop, a teacher at the University of National Economy, was quoted as saying.