Kim Jong-un praised the "perfect success" of the country's sixth and largest nuclear test and urged further weapons development, according to state media Sunday, in the face of a US drive for tough new sanctions.
Pyongyang held a banquet, concert and performances in a weekend display of pageantry to celebrate the September 3 nuclear test, which the North said was a hydrogen bomb that could be fitted onto a rocket.
The blast, which came weeks after the country fired off two intercontinental ballistic missiles (ICBMs) that appeared to bring much of the mainland US into range, prompted global condemnation and calls to ramp up sanctions against the isolated nation.
But the North's leader appeared deaf to the international outrage and hailed the "perfect success in the test of H-bomb" at a dinner to congratulate the scientists and technicians behind the nuclear programme, the official Korean Central News Agency reported Sunday.
Dubbing the latest test the "great auspicious event of the national history", he called for "redoubled efforts" to complete the country's mission to fully become a recognised nuclear power.
A two-page spread carried by the North's official Rodong Sinmun newspaper on Sunday showed photos of Kim and his wife Ri Sol-Ju attending a special concert held for the nuclear scientists and technicians.
A slew of brazen tests in recent months, which contravene existing United Nations sanctions, has sparked surging tensions over the North Korean weapons programme.
Pyongyang says it needs nuclear arms to protect itself, but the US has accused the isolated nation of "begging for war".
In an interview published on Sunday, United Nations Secretary General Antonio Guterres said the showdown over North Korea's nuclear and missile programme was the world's worst crisis "in years" and had left him deeply worried.
"We have to hope that the seriousness of this threat puts us on the path of reason before it is too late," Guterres said in the French Sunday newspaper Le Journal du Dimanche.
He also called for unity in the UN Security Council, which is set to consider a new draft resolution presented by Washington in recent days that would be the toughest-ever imposed on North Korea.
The US is calling for an oil embargo on the North, an assets freeze on Kim Jong-Un, a ban on textiles and an end to payments of North Korean guest workers.
It is hoping for a Monday vote though both China and Russia are thought to have raised opposition to the measures.