'A real threat to our peace': Why Turnbull's alarmed by North Korea's missile test over Japan

There are fresh concerns North Korea's weapons can reach Australia's top end after the rogue state fired a missile over the north of Japan on Tuesday in a "serious escalation" of its threats against the west.

Nuclear-armed North Korea fired a ballistic missile over Japan and into the Pacific Ocean in what was the first to fly over the peninsula in many years.

Darwin is slightly more than 5,700km from North Korea but Pyonyang claims its first intercontinental ballistic missile can reach lengths of 6,700km.

Prime Minister Malcolm Turnbull and Foreign Minister Julie Bishop adamantly condemned the act of "reckless provocation".

"This is yet another very dangerous move by North Korea ... it poses a very real threat to peace in our region," Mr Turnbull told ABC radio on Wednesday.

Prime Minister Malcolm Turnbull. Source: AAP

The North Korean missile was launched over Japan early Tuesday. Source: 7 News

Foreign Minister Julie Bishop condemned the "provocative, dangerous, destabilising and threatening act" and assured the Australian public that she would "keep our region safe".

"The concern is now that North Korea will master the technology to mount a nuclear warhead on such a weapon," Ms Bishop said.

"We have seen this pattern of behaviour by the North Korean regimes over a number of decades."

Nuclear-armed North Korea fired a ballistic missile over Japan and into the Pacific Ocean on Tuesday in what was the first to fly over the peninsula in many years. Source: AP

Japan's Air Self-Defense Force undergoes drills. Source: AP

The rogue nation recently threatened to fire a salvo of missiles towards the US territory of Guam, while US President Donald Trump issued an apocalyptic warning of raining "fire and fury" on the North.

Tensions had eased more recently, but the South's joint chiefs of staff said in a statement that Tuesday's missile was launched at around 2057 GMT (6.57amAEST) Monday from Sunan, near Pyongyang, travelling east "and over Japan".

Foreign Minister Julie Bishop condemned the "provocative, dangerous, destabilising and threatening act".

It flew around 2,700 kilometres at a maximum altitude of around 550 kms it said, adding South Korea and the US were "closely analysing for more details".

Guam is around 3,500 kms from North Korea - although the missile appeared to have been fired in a westerly direction and not towards the US outpost, home to about 160,000 people and host to major military facilities.

A woman stops as a TV screen on a street in Tokyo broadcasts news of North Korea's ballistic missile launch. Source: AP

Tokyo also said the missile flew over the country's northernmost island Hokkaido, with Prime Minister Shinzo Abe saying the government would take "full steps" to ensure the safety of the Japanese people.

"Their outrageous act of firing a missile over our country is an unprecedented, serious and grave threat and greatly damages regional peace and security," he told reporters.

The US confirmed the launch and the overflight of Japan, with Pentagon spokesman Colonel Rob Manning saying the North American Aerospace Defense Command (NORAD) determined it "did not pose a threat to North America".

The firing comes days after Pyongyang launched three short-range missiles in what analysts said was seen as a minimal provocation after the start of the Ulchi Freedom Guardian South Korean-US joint military exercise.

The North, which says it needs nuclear weapons to protect itself, sees the drills as rehearsals for invasion.

But Tuesday's flight path represents a significant escalation by Pyongyang.

Newsbreak - August 29