Prime Minister Malcolm Turnbull has accused China of not doing enough to control the reclusive North Korean regime, which has threatened a nuclear attack on the United States.

Key points: World concerned about "reckless and dangerous" conduct of North Korea, Malcolm Turnbull says

World concerned about "reckless and dangerous" conduct of North Korea, Malcolm Turnbull says Christopher Pyne says North Korea poses "greatest threat" to global security

Christopher Pyne says North Korea poses "greatest threat" to global security Mr Turnbull stressed sanctions, "other means" to put pressure on the regime

Last week that threat led US President Donald Trump to declare that he would "solve the problem" of North Korea with or without China, which shares a border with the regime.

Speaking in India today, Mr Turnbull said the entire world was concerned about the "reckless and dangerous" conduct of the North Korean regime, which threatens regional stability and global peace.

"The time has come for all parties — but particularly China, which has the closest relationship with North Korea — to bring pressure to bear through the sanctions regime and other means to ensure they cease this reckless and dangerous conduct," he said.

Mr Turnbull said China was "clearly not doing enough" to control North Korea.

"The Chinese side would say they have imposed some sanctions, but the reality is the regime is threatening peace and stability in the world," he told Sky News.

"The Chinese are the parties with the greatest leverage over North Korea, that's a fact."

North Korea poses 'greatest threat' to global security, Pyne says

Late last year, China, which is believed to be the only country buying North Korean coal, announced it would slash its imports in line with international sanctions after a ballistic missile test.

US officials have stressed that stronger sanctions are the most likely US course to press North Korea to abandon its nuclear program.

Mr Trump has accused North Korea of "looking for trouble" and recently diverted a US Navy strike group towards the peninsula as a show of force amid concerns about its nuclear program.

Earlier on Wednesday, Defence Industry Minister Christopher Pyne said the North Korean regime was unpredictable and posed the "greatest threat" to global security.

"We welcome the US taking a firm line with North Korea and as Malcolm Turnbull has said, it is very important that China takes full responsibility for what it can do to settle that part of the world," he said.

Mr Pyne said the unpredictability of the regime was "of significant consequence to Australia".

"I know it seems surprising to say so, but there is a predictability about the war in the Middle East, in Syria and Iraq, and of course the allies there are winning that war slowly but surely," he told Adelaide radio station 5AA.

Washington officials have said all options, including military ones, are on the table and that a US strike last week against Syria should serve as a warning to Pyongyang.

White House spokesman Sean Spicer said Mr Trump had put North Korea "clearly on notice" that he would not tolerate certain actions, but dismissed Pyongyang's nuclear attack threat.