Malcolm Turnbull is calling for the economic pressure on North Korea to be ratcheted up as he likened the rogue nation to the mafia.
After US President Donald Trump warned that talking was not the answer, the prime minister agreed military conflict was an option to deal with Pyongyang - but not the only one.
"They're stand-over merchants. What they're seeking to do is intimidate other countries to not impose sanctions and that's why the sanctions must be imposed," Mr Turnbull told the Seven Network on Thursday.
He later made another comparison on WSFM radio.
"It's like the mafia," he said.
Mr Turnbull said the global community was absolutely united in standing up to the Kim Jong-un regime, citing tougher sanctions that come into effect next week.
"If North Korea were to attack the United States, as they often threaten to do, there would be a conflict which would be a suicide note from North Korea's point of view," he said.
"Kim Jong-un is playing a game of very, very dangerous brinkmanship."
Mr Turnbull again called on China to use its significant economic leverage to bring North Korea to its senses without conflict.