Just a month after North Korea's fourth nuclear test, the country's announced the launch of a long-range rocket to put a satellite into orbit.
International analysts and leaders believe it was a ballistic missile test.
Japan's Ambassador to the United Nations, Motohide Yoshikawa, says many countries - including his own - were placed in danger by the launch.
"There was unity of the security council in the outrage (over) the missile launch. This is the area where there is a very dense maritime and air transportation, which had also been disrupted so we have to take this issue very seriously. It's not only the violation of the Security Council resolutions, but it is the real threat."
South Korea, Japan and the United States called emergency talks to agree on a collective response to the launch.
The UN Security Council was in the process of deciding on more sanctions against North Korea, following its earlier missile tests.
Samantha Power is the US Ambassador to the UN.
She says the launch undermines regional stability and violates obligations under four separate Security Council resolutions.
"Pyongyang claims it launched what it called a peaceful earth observation satellite. But nobody is fooled. So-called space launch vehicles are the same technology as ballistic missiles which are expressly prohibited. What North Korea is doing with each of these acts, these illegal acts, with each of these launches, is the launches themselves are advancing North Korea's capacity to advance its nuclear weapons program."
South Korea's ambassador to the UN, Oh Joon, describes the launch as totally outrageous and unacceptable.
"As a Korean it is sad, almost pathetic, to watch staged celebrations on the streets of Pyongyang as I know that the cost of this launch alone, estimated to be close to $1 billion, could have fed the entire North Korean population for a whole year."
South Korean President Park Geun-hye says the timing of the launch is a direct challenge to the international community.
"In addition to disregarding the international community's warnings and conducting its fourth nuclear test in the morning of the lunar New Year, North Korea again committed an intolerable provocation of launching a long-range missile. Also, considering that this time's missile launch was conducted when UN Security Council resolutions discussions are going on."
North Korea's main ally, China, has expressed regret at the rocket launch but called on all parties to prevent further escalation.
Chairman of South Korean National Assembly's Intelligence Committee, Joo Ho-young, says the launch displayed some improvements in North Korea's weaponry.
"Considering the flight time, stage separation, and spot where the fuselage fell, it seems that it flew normally and disengaged in parts, and we are still in the process of confirming the normal operation of the satellite. Through this time's launch, it is judged that they have accumulated intercontinental ballistic missile technologies, including stage separation and missile guidance, to some degree."
But North Korea's technology is far from complete.
The rocket's payload was presumed to weigh 200 kilograms, which is double the size of the one launched in 2012, but much lighter than the 800 to 15,000 kilograms usual for a satellite.
It has not tested re-entry for its long-range missiles and appears unable to carry a nuclear warhead capable of reaching the United States.
Still, the United States and South Korea have agreed to hold informal discussions on improving its missile defence systems.
