The launch of three missiles yesterday by Pyongyang comes at a time when a small crack seems to have appeared in the international show of unity against North Korea's development of nuclear weapons, after the "secret" visit to Pyongyang last week by a special adviser to Japanese Prime Minister Shinzo Abe.
The firing of the missiles follows recent rhetoric from the Kim Jong-un regime threatening nuclear strikes against the US and moving the medium-range Musudan missiles to North Korea's east coast. The warnings led the United States, South Korea and Japan to boost defences and raised concern in Beijing, Pyongyang's biggest ally.
South Korean President Park Geun-hye has not convened a National Security Council meeting because the projectiles did not appear to be Musudan, said Kim Haing, her spokeswoman.
The launches also came a day after Abe's aide Isao Iijima left Pyongyang following an unannounced four-day trip.
Tokyo's decision to engage with North Korea was apparently known initially to only a handful of officials at the prime minister's office; Tokyo had not even notified its regional partners of Iijima's travel plans, to barely concealed irritation in Seoul and Washington.
South Korea's Foreign Ministry called Iijima's trip "unhelpful" in co-ordinating international efforts to resolve the North Korean nuclear issue, as Glyn Davies, top US envoy on North Korea, travelled to South Korea, China and Japan last week.
Abe refused to comment on the purpose of Iijima's visit, but it has become apparent that Tokyo has spied an opportunity to make progress on a subject close to the prime minister's heart - the abduction of 17 Japanese citizens by North Korean agents between 1977 and 1983.
"We are paying constant attention to nuclear and missile developments in North Korea," Naoko Saiki, Japan's deputy Foreign Ministry spokeswoman, said yesterday, declining to comment further "because it relates to an intelligence matter".
The US and South Korea have repeatedly called on China to make greater efforts to enforce sanctions targeting the North's nuclear-weapons development programme.
"The missile launch by North Korea is something that no other countries want to see, and China's reaction will be predictable. The government will likely condemn any action threatening the peace and stability in the peninsula," said Professor Wang Fan , director of the Institute of International Relations of China Foreign Affairs University.
"I don't think North Korea had notified China in advance. In the past it had given China short notice, but recently it had learned China's stand on such issues and knew that China would oppose it, so it might have saved the effort."
Bloomberg, Christian Science Monitor, Agence France-Presse