North Korea has claimed to have successfully carried out its fifth nuclear test - just hours after an earthquake was detected near its nuclear test site.
The South Korean President Park Geun-hye has slammed the test, saying the act of "self-destruction" presented a serious challenge for the global community, and showed North Korea's "maniacal recklessness".
Park said: "What the Kim Jong-un regime will get from the nuclear test is stronger international sanctions and deeper isolation. This kind of provocation would just hasten its self-destruction."
With fears mounting that North Korea could be moving toward obtaining a fully-functional nuclear weapon, the Chinese foreign ministry said it was opposed to the test, and advised North Korea not to take any more inflammatory actions.
President of the US Council on Foreign Relations, Richard Haass, tweeted that the latest test will be another test of China's mettle towards its isolated neighbour.
N Korea emerging as most critical test of willingness of China, NK's lifeline, to act as responsible power. Thus far it has failed to do so— Richard N. Haass (@RichardHaass) September 9, 2016
US President Barack Obama said: "We will continue to put some of the toughest pressure that North Korea has ever been under as a consequence of this behaviour.
"Can I guarantee that it works? No. But it is the best options that we have available to us right now."
The test was detected as a 5.3 magnitude earthquake in the north-east of North Korea, near to an underground nuclear test site. South Korea said its measurements of the seismic event showed the test was the strongest event conducted by North Korea.