Australia will pressure North Korea into ending 'provocative behaviour': Julie Bishop

Australia will work with other countries to put pressure on North Korea to end its "provocative behaviour", Foreign Minister Julie Bishop says.

Ms Bishop described the actions of the regime as a threat to international peace and security, saying the United Nations Security Council has agreed to take further significant measures after the rogue nation conducted a fourth nuclear test.

"We will continue to work with partners and allies, and the rest of the international community to place pressure on North Korea so it stops this provocative behaviour," she told the TODAY Show this morning.

Ms Bishop said the key to sanctions having an impact is ensuring countries don't trade with North Korea, so China will be key.

But she believes China is as "frustrated" as the rest of the international community with the regime and there is a "united effort" to impose greater sanctions.

The minister said the regime's leader Kim Jong Un is more unpredictable than his father and harder to read.

It is not yet clear what type of bomb North Korea detonated.

"If it were a hydrogen bomb, that is a significant and dangerous step forward by North Korea," she later told the Seven Network.

Overnight Ms Bishop spoke with her South Korean counterpart, who is deeply concerned about what the test means for stability in the Korean peninsula.