"We strongly deplore the nuclear test conducted by the DPRK," BRICS said in a joint statement from its annual summit, using the acronym of North Korea's official name.
BRICS is made up of Brazil, Russia, India, South Africa and summit host China - North Korea's long-time patron.
Pakistan condemns North Korea’s hydrogen bomb test
"We express deep concern over the ongoing tension and prolonged nuclear issue on the Korean Peninsula," said the declaration from the summit in the south-eastern Chinese city of Xiamen.
It added that BRICS believes the issue "should only be settled through peaceful means and direct dialogue of all the parties concerned."
North Korea on Sunday triggered global alarm with by far its most powerful nuclear blast to date. It claimed it had successfully tested a hydrogen bomb that could be mounted onto a long-range missile.
The North - which in July carried out two intercontinental ballistic missile launches that apparently brought much of the US mainland into range - has made rapid progress with its weapons programme, in defiance of seven sets of UN sanctions.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ