North Korea carries out largest nuclear test ever

A fifth nuclear test by North Korea drew immediate condemnation from the international community and raised concerns the country might have made significant progress in its nuclear programme due to its potency.

According to South Korea's Meteorological Administration, the blast had an explosive force of 10 kilotons, twice that of the previous test and the secretive nation's most powerful detonation to date.

The blast triggered an earthquake of magnitude 5.3 near the test-site.

North Korea confirmed the test on its state TV channel, in an act which signals the country's lack of regard for UN sanctions imposed on it in January this year, and will put the United States and South Korea on high alert.

The KCNA news report said its "scientists and technicians carried out a nuclear explosion test for the judgement of the power of a nuclear warhead".

The blast coincided with the anniversary of the country's foundation as a Republic in 1948.

Previously on Thursday, US president Barack Obama had raised concerns surrounding the nuclear power of the Kim Jong-un led government.

"We are going to make sure that we put our defensive measures in place so that America is protected, our allies are protected," Obama said during an ASEAN summit in Laos.

"We will continue to put some of the toughest pressure that North Korea has ever been under as a consequence of this behavior."

Japanese prime minister Shinzo Abe said the test was "absolutely unacceptable", while South Korea's president Park Geun-hye described it as an act of "self-destruction".