Japan has expressed concern about the growing military threat from North Korea, hours after the regime carried out its most successful test yet on a powerful medium-range missile that is capable, in theory, of striking US bases in the region.
“The threat to Japan is intensifying,” Gen Nakatani, the Japanese defence minister, said after the second of two Musudan missiles launched by the North on Wednesday morning flew 250 miles (400km).
That was the longest distance a Musudan has achieved to date and equivalent to more than halfway to the south-west coast of Japan’s main island, Honshu.
Experts said North Korea appeared to have launched the second missile on an unusually high trajectory so that it would avoid violating Japanese air space.
The missiles are usually test-fired at a flatter angle to maximise their range, according to Jeffrey Lewis at the Middlebury Institute of International Studies in California. “That suggests the missile worked perfectly,” he said. “Had it been fired at its normal angle, it would have flown to its full range.”
Lewis warned that North Korea would eventually iron out any technical problems with the Musudan and then use the lessons to increase the threat to the US. “If North Korea continues testing, eventually its missileers will use the same technology in a missile that can threaten the United States,” he said.
It was not immediately clear whether Pyongyang considered the second Musudan launch a success or failure, or how the flight ended.
But it appeared to have been more successful than the first launch two hours earlier, which ended when the missile disintegrated mid-flight after covering about 90 miles, according to South Korea’s Yonhap news agency.
The second Musudan, launched from the same east location as the first, reached an altitude of 620 miles – an indication, Nakatani said, that the country was making progress in its programme to develop a reliable intermediate-range weapon capable of hitting targets that could include South Korea, Japan and the US Pacific territory of Guam.
The launches also demonstrate the determination of the North Korean leader, Kim Jong-un, to defy UN security council resolutions banning North Korea from developing ballistic missile technology.
“These provocations only serve to increase the international community’s resolve to counter [North Korea’s] prohibited activities, including through implementing existing UN security council sanctions,” US state department spokesman John Kirby said.
“We intend to raise our concerns at the UN to bolster international resolve in holding [North Korea] accountable for these provocative actions.”
Japan’s prime minister, Shinzo Abe, said the launches were a clear violation of security council resolutions, adding that Japan would “respond to the situation through coordination with the United States and South Korea”.
The first launch on Wednesday is thought to have been the fifth time in a row the regime has failed to successfully fire a Musudan, which has an estimated range of between 1,550 and 2,485 miles.
In April, North Korea attempted unsuccessfully to launch three suspected Musudan missiles, but all exploded in mid-air or crashed, according to South Korean defence officials. Late last month, North Korea had another suspected Musudan failure, South Korean officials said.
Nakatani described the launches as a “serious provocation”, while South Korea was to hold a meeting of national security experts to discuss the Musudan threat.
The South Korean president, Park Geun-hye, said repeated missile and nuclear tests had set North Korea on the path to self-destruction. “The North Korean regime should realise that complete isolation and self-destruction await at the end of reckless provocation,” Park said.
North Korea is believed to have up to 30 Musudan missiles, which officials said were first deployed around 2007, although the North had never attempted to test-fire them until April this year.
Yonhap quoted an unidentified senior government official in Seoul as saying that the second test demonstrated an obvious “improvement in capacity and technology”.
The UN security council, with the support of the North’s main diplomatic ally China, imposed new sanctions in March after Pyongyang conducted its fourth nuclear test and launched a long-range rocket.
North Korea claimed the rocket was carrying an observation satellite, but the launches are seen as an opportunity for the state to test ballistic missile technology.