Turnbull welcomes Trump's N Korea meeting

Malcolm Turnbull says the meeting between US President Donald Trump and North Korea's Kim Jong-un is welcome, but he remains cautious.

The date and location of the first-ever meeting of a sitting US president and a North Korean leader was announced by Mr Trump on Twitter on Thursday.

"The highly anticipated meeting between Kim Jong Un and myself will take place in Singapore on June 12th. We will both try to make it a very special moment for World Peace!" Mr Trump wrote.

The president faces a difficult task persuading Mr Kim to abandon nuclear weapons and ballistic missile tests that heightened US-North Korean tensions throughout 2017.

The two men exchanged fiery rhetoric last year over North Korea's attempts to build a nuclear weapon that could reach the United States.

But tensions have since eased, starting around the time of the North's participation in the Winter Olympics in South Korea in February.

"We welcome the scheduled meeting," Mr Turnbull told reporters in Sydney on Friday.

"The strength of the sanctions that have been brought to bear on North Korea have the consequence of bringing North Korea this far."

But Mr Turnbull said he remained cautious about North Korea's intentions, because there had been "false dawns" before.

Foreign Affairs Minister Julie Bishop is hopeful the meeting will be a circuit-breaker for North Korea's illegal behaviour.

"We hope that the summit will result in an agreed plan whereby North Korea denuclearises - in other words dismantles - its illegal nuclear weapons and ballistic missiles programs," Ms Bishop said.

"We want to see peace on the Korean Peninsula, but a first step must be for North Korea to show genuine action in denuclearising."