NORTH KOREAN MISSILE LAUNCH: SOUTH WARNS IT CAN DESTROY NORTH BEYOND RECOVERY

The United Nations Security Council has condemned North Korea's latest missile launch as an "outrageous action" after it was called into an emergency session to discuss Pyongyang's longest-ever test flight of a ballistic missile.

Key points:

*North's intermediate-range weapon launch on Friday signalled defiance of rivals

*President Moon Jae-in says South has strength to "inflict a level of damage it would be impossible to recover from"

*Annual gathering of world leaders at General Assembly will discuss North Korea

South Korean President Moon Jae-in, a liberal who initially pushed for talks with North Korea, said its tests currently made dialogue "impossible".

"The sanctions and pressure by the international community will only tighten so that North Korea has no choice but to take the path for genuine dialogue [for nuclear disarmament]," Mr Moon said.

"If North Korea provokes us or our allies, we have the strength to smash the attempt at an early stage and inflict a level of damage it would be impossible to recover from.

North Korea's Rodong Sinmun newspaper said, without mentioning the latest missile test, that its weapons' tests demonstrate that it can "turn the American empire into a sea in flames through sudden surprise attack from any region and area".

"The Security Council stressed that these [North Korea] actions are not just a threat to the region, but to all UN member states," the 15-member council said in a statement.

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The United States has also stepped up its rhetoric, saying it had military options to deal with North Korea and that it was fast running out of patience for diplomatic solutions on the country's missile and nuclear programs.

"We've been kicking the can down the road, and we're out of road," White House National Security Adviser HR McMaster told reporters, referring to Pyongyang's repeated missile tests in defiance of international pressure.

"For those … who have been commenting on a lack of a military option, there is a military option."

However, he said that it would not be the Trump administration's preferred choice.

The US ambassador to the United Nations, Nikki Haley, echoed Mr McMaster's strong comments, even as Washington continued to emphasise that its preferred resolution to the crisis is through diplomacy and sanctions.

"What we are seeing is, they are continuing to be provocative, they are continuing to be reckless and at that point there's not a whole lot the Security Council is going to be able to do from here — when you've cut 90 per cent of the trade and 30 per cent of the oil," Ms Haley said.

North Korea wants to establish 'equilibrium of real force'

US President Donald Trump also spoke out after the latest missile tests, saying that he was "more confident than ever that our options in addressing this threat are both effective and overwhelming".

Speaking to a group that included military personnel at Joint Base Andrews near Washington, Mr Trump said North Korea "has once again shown its utter contempt for its neighbours and for the entire world community".

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Meanwhile, North Korea's state agency said on Saturday (local time) that its goal was reaching "equilibrium" of military force with the US.

"Our final goal is to establish the equilibrium of real force with the US and make the US rulers dare not talk about military option for the DPRK," Mr Kim was cited as saying in the report.

The intermediate-range weapon North Korea launched early on Friday from Sunan, the location of Pyongyang's international airport, hurtled over US ally Japan into the northern Pacific Ocean.

The launch signalled both defiance of North Korea's rivals and a big technological advance.

It followed a UN council meeting on Monday, which unanimously approved its toughest sanctions yet on North Korea over its nuclear test, which Pyongyang said was a hydrogen bomb.

The US said the measures, including a ban on textile exports, combined with previous sanctions would ban over 90 per cent of North Korea's exports reported in 2016.

North Korea's Foreign Ministry denounced the sanctions and said the North would "redouble its efforts to increase its strength to safeguard the country's sovereignty and right to existence".

Since Mr Trump threatened North Korea with "fire and fury" in August, the North has conducted its most powerful nuclear test, threatened to send missiles into the waters around the US Pacific island territory of Guam and launched two missiles of increasing range over Japan.

July saw the country's first tests of intercontinental ballistic missiles that could strike deep into the US mainland when perfected.

The growing frequency, power and confidence displayed by these tests seem to confirm what governments and outside experts have long feared: North Korea is closer than ever to its goal of building a military arsenal that can viably target US troops both in Asia and in the US homeland.

This, in turn, is meant to allow North Korea greater military freedom in the region by raising doubts in Seoul and Tokyo that Washington would risk the annihilation of a US city to protect its Asian allies.

South Korea responds with its own missile launch

North Korea has repeatedly vowed to continue its weapons tests amid what it calls US hostility — by which it means the presence of nearly 80,000 US troops stationed in Japan and South Korea.

Robust international diplomacy on the issue has been stalled for years, and there is so far little sign that senior officials from North Korea and the US might sit down to discuss ways to slow the North's determined march toward inclusion among the world's nuclear weapons powers.

Friday's test, which Seoul said was the 19th launch of a ballistic missile by North Korea this year, triggered sirens and warning messages in northern Japan but caused no apparent damage to aircraft or ships.

It was the second missile fired from Sunan over Japan in less than a month.

South Korea detected North Korean launch preparations on Thursday, and President Moon ordered a live-fire ballistic missile drill if the launch happened.This allowed Seoul to fire its missiles only six minutes after the North's launch on Friday.

One of the two missiles hit a sea target about 250 kilometres away, which was approximately the distance to Pyongyang's Sunan, but the other failed in flight shortly after launch, South Korea's Joint Chiefs of Staff said.

South Korea's Joint Chiefs of Staff said the latest missile travelled about 3,700 kilometres and reached a maximum height of 770 kilometres.

Guam, which is the home of important US military assets, is 3,400 kilometres away from North Korea.

"The range of this test was significant since North Korea demonstrated that it could reach Guam with this missile," the Union of Concerned Scientists advocacy group said in a statement.

However, the accuracy of the missile, still at an early stage of development, was low, it said.

This was echoed by US missile expert with the Union of Concerned Scientists David Wright, who said that despite its impressive range, the missile probably still is not accurate enough to destroy Guam's Andersen Air Force Base.