North Korea's latest missile test marks a significant step forward towards Kim Jong-un's regime producing an ICBM capable of hitting the US mainland, experts have warned.

The dictator's defence ministry fired a missile named Hwasong-12 on Sunday night which soared 489 miles (787 km) reaching a height of 1,312 miles (2,111 km).

The test 'represents a level of performance never before seen from a North Korean missile', John Schilling, an aerospace expert, said in an analysis on the US-based 38 North website.

'It appears to have not only demonstrated an intermediate-range ballistic missile (IRBM) that might enable them to reliably strike the US base at Guam, but more importantly, may represent a substantial advance to developing an intercontinental ballistic missile (ICBM).'

Sunday's missile was deliberately fired at the highest angle to avoid affecting neighbouring countries' security, but had it been launched at a standard trajectory, it would have reached at least 2,500 miles (4,000km) - almost half the 5,500 miles (8,851 km) required to reach the US mainland.

This graphic shows how an ICBM works and how far off the missile North Korea launched on Sunday was from reaching the US mainland. If it had been fired at a standard trajectory (marked in red) it would have reached almost halfway across the Pacific. Instead, it was tested at a steep angle (in yellow) to avoid affecting neighbouring countries' security

North Korean leader Kim Jong Un inspects the long-range strategic ballistic rocket Hwasong-12 ahead of the launch

Kim Jong-Un, North Korea's leader, stands underneath a huge missile which was said to have been launched on Sunday

The long-range strategic ballistic rocket Hwasong-12 (Mars-12) is launched during a test in this undated photo released by North Korea's Korean Central News Agency (KCNA) on May 15, 2017

South Korea's defence minister said on Tuesday that the launch shows Kim's missile programme is progressing faster than expected.

The details of Sunday's launch reported by KCNA were largely consistent with South Korean and Japanese assessments in that it flew further and higher than an intermediate-range missile (IRBM) tested in February from the same region, northwest of Pyongyang.

How far would missile have to travel from Pyongyang to reach the rest of the world? US Naval Base in Guam: 2,114 miles (3,402 km) Hawaii: 4,727 miles (7,670 km) London (over mainland Europe): 5,379 miles (8,657 km) San Francisco: 5,588 miles (8,993 km) Los Angeles: 5,935 miles (9,551 km) Washington, DC: 6,857 miles (11,035 km) Advertisement

KCNA said the test launch verified the homing feature of the warhead that allowed it to survive 'under the worst re-entry situation' and accurately detonate.

The claim, if true, could mark an advancement in the North's ICBM program exceeding most expectations, said Kim Dong-yub, a professor at Kyungnam University's Institute of Far Eastern Studies in Seoul.

The reclusive North, which has defied all calls to rein in its weapons programmes, even from its lone major ally, China, has been working on a missile, mounted with a nuclear warhead, capable of striking the US mainland.

US President Donald Trump's administration has called for an immediate halt to Pyongyang's provocations and has warned that the 'era of strategic patience' with North Korea is over.

US Disarmament Ambassador Robert Wood said on Tuesday China's leverage was key and that it could do more.

South Korean Defence Minister Han Min-koo told parliament Sunday's test-launch was 'successful in flight'.

Asked if North Korea's missile programme was developing faster than the South had expected, he said: 'Yes.'

North Korean leader Kim Jong Un laughing during the long-range strategic ballistic rocket Hwasong-12 (Mars-12) test launch in this undated photo released by North Korea's Korean Central News Agency (KCNA)

The latest missile launch represents a significant step forward in its weapons capabilities, analysts say, but Pyongyang could be looking to secure a position of strength before a return to the negotiating table.

The intermediate-range missile fired by the North at the weekend was its longest-range rocket yet, according to experts.

It was its 10th launch this year, after dozens in 2016, as it accelerates efforts to develop an intercontinental ballistic missile (ICBM) capable of delivering a nuclear warhead to the continental United States - something President Donald Trump has vowed 'won't happen'.

Melissa Hanham of the Middlebury Institute of International Studies in California said: 'Kim Jong-Un has stepped up testing compared to his father and grandfather, and it is starting to pay off. This is a clear indication of progress.'

A still image taken from the video said to show the launch of the missile on Sunday

Pyongyang has long had missiles that can reach targets across the South - the 311-mile (500 km) Scud - and Japan, the 621-808 mile (1,000-1,300 km) Rodong.

But with a supposed range of 2,796 miles (4,500 km), the Hwasong-12 puts US bases on the Pacific island of Guam within reach.

It is still some way off the 4,727 miles (7,670 km) needed to reach Hawaii, the 5,935 miles (9,551 km) to Los Angeles or the 6,857 miles (11,035 km) to Washington, DC, but the new missile could be a stepping stone to a properly working ICBM - which would fundamentally change assessments of the threat posed by Pyongyang.

Expert John Schilling added: 'This is not that missile but it might be a testbed, demonstrating technologies and systems to be used in future ICBMs.'

Pyongyang 'may be closer to an operational ICBM than had been previously estimated', he said on the respected 38 North website.

A functional ICBM would need a nuclear warhead that can be mounted on to a missile.

The North's official Korean Central News Agency claimed the latest test had proved its guidance and re-entry technologies, and said the rocket was 'capable of carrying a large-size heavy nuclear warhead'.

It was 'plausible that they have made a compact warhead after five nuclear tests', Hanham said, but KCNA's phrasing was 'interesting but vague'.

'It's really hard to take their claims seriously without verification from other governments,' she added.

The North's leader, has said it was in final stages of developing an ICBM.

It was difficult to say when the North will have a reliably tested ICBM ready to deploy, said Lee Choon-geun, a senior research fellow at South Korea's state-run Science and Technology Policy Institute.

'When it comes to actual deployment, developed countries have tested at least 20 ICBMs and their success rate should be around 90 percent. It is not there yet,' he said.

But the new engine used for Sunday's test signaled a major step forward in the intermediate-range missile development, one that can be modified for an ICBM flight, Lee added.

Missile launch poses challenge to South Korea's new left President The launch came just four days after the inauguration of South Korea's new left-leaning President Moon Jae-In, who advocates reconciliation and dialogue with Pyongyang to curb its nuclear ambitions. Moon was part of the South's last liberal government nearly a decade ago, which pursued a 'Sunshine policy' of engagement with the North, and declared at his swearing-in that he would go to Pyongyang 'in the right circumstances'. Instead, said Koo Kab-Woo of Seoul's University of North Korean Studies, he had been posed 'an extremely difficult question' by the launch. 'Under the current circumstances, it's very hard' to hold any talks with the North, Koo said. But the timing of the launch so close to Moon's installation was largely coincidental, he said. 'They are just going their way consistently towards the goal of attaining nuclear deterrence capability.' Moon slammed the launch as a 'reckless provocation' saying that dialogue would be possible 'only if Pyongyang changes its behaviour'. The North 'strongly wants to talk with Washington', Koo said, as expressed by a senior North Korean official following a meeting with former US officials in Oslo, Norway. That remark came just two weeks after President Donald Trump said he would be 'honoured' to meet Kim, after their tit-for-tat sabre-rattling raised tensions in the region. Pyongyang insists it needs nuclear weapons to defend against the threat of invasion by the US, and shows no indication of any willingness to give them up, whatever concessions are offered. The North's young leader is more focused on presenting Pyongyang to Washington and Beijing as their equals, equipped with weapons as devastating as their own, said Choi Kang of the Asan Institute for Policy Studies in Seoul. 'The bigger you are, the bigger the advantage you will have over negotiations. Otherwise, you will be looked down on,' he said. 'In the Kim Jong-Il era, North Korea launched missiles to get Washington's attention,' he said. 'But now it's different.' Advertisement

North Korea's official Rodong Sinmun newspaper devoted half of its six-page Monday edition to coverage of the missile test, with vivid color photographs of the launch and jubilant leader Kim celebrating with military officers.

The pictures featured a long nose-coned projectile that appeared to be similar to missiles displayed during an April 15 military parade for the birth anniversary of state founder Kim Il-Sung, the current leader's grandfather.

The nose cone resembles that of the KN-08 ICBM the North is believed to be developing, and the lofted trajectory tests re-entry by putting the missile through extra stress, said Joshua Pollack of the US-based Nonproliferation Review.

'This is an advanced missile, if their claims are true,' he said.