The UN Security Council is holding an emergency meeting following North Korea s launch of a long-range rocket.
The meeting was requested by South Korea, Japan and the US to agree on a collective response to the launch.
Pyongyang said it fired the rocket to place a satellite in orbit, but critics believe the real purpose was to test a ballistic missile.
Sunday s launch comes weeks after North Korea held a fourth nuclear test both acts violate UN resolutions.
We have consensus to condemn this kind of violation of sanctions, Venezuela s UN envoy Rafael Ramirez, who holds the Council presidency, said ahead of the closed-door meeting in New York.
French ambassador Francois Delattre described Pyongyang s move as an outrageous provocation.
That s why weakness is not an option, he added.
The launch of the rocket was hailed by North Korean media as a fascinating vapour trailing in the clear and blue sky in spring of February on the threshold of the Day of the Shining Star .
A statement said a new Earth observation satellite, Kwangmyongsong-4, had successfully been put into orbit less than 10 minutes after lift-off from the Sohae space centre in North Phyongan province.
Hailing it as part of the country s peaceful space programme, a state TV newsreader said the launch had been ordered by North Korea s leader Kim Jon-un and more satellite launches were planned for the future.
South Korean MPs were told by the country s spy agency later on Sunday that the launch should be treated as a ballistic missile test as the satellite it put into orbit would be useless.
The payload was presumed to weigh 200kg (440lbs), double the size of the one launched in 2012, but much lighter than the 800-1,500kg usual for a satellite.
The MPs were also reportedly told that North Korea had the technology for intercontinental ballistic missiles and was preparing a fifth nuclear test.
Analysis: BBC s John Sudworth in Beijing
Sunday s launch does not significantly alter the strategic balance of power in North East Asia. It is not the first time North Korea has attempted to put an object into space using a long-range rocket.
But it is nonetheless a highly-provocative act, hence the reaction from Seoul, Tokyo and Washington, calling it unforgivable and intolerable .
The significance is in the timing, with the launch coming just a month after the North s fourth nuclear test and with the UN Security Council in the middle of weighing its sanctions response.
Beijing too is unlikely to be under any illusion that the real purpose here is the test of the missile itself. After all, if Pyongyang wanted to put up satellites it could pay its old ally to do so at a fraction of the price.
But China is, as always, treading a careful line, issuing a nuanced statement of regret .
Its biggest fear is pushing an already isolated and heavily sanctioned neighbour towards economic and political collapse.
And so while each such rocket launch takes North Korea one more step towards its stated goal of a deliverable nuclear weapons system (although probably still years away) the international impasse over what to do about it is likely to continue.
Nato said the launch was in direct violation of five UN Security Council resolutions.
China a key ally of Pyongyang s said it regrets North Korea s actions but urged the relevant parties to refrain from taking actions that may further escalate tensions on the Korean peninsula .
US Secretary of State John Kerry warned of significant measures to hold the DPRK North Korea to account.
North Korea last fired a long-range rocket in 2012 to put, what it said was, a communications satellite into orbit.
But experts say no signal has ever been detected.
UN Security Council resolutions ban the state from carrying out any nuclear or ballistic missile tests.
The North insists its space programme is purely scientific in nature but the US, South Korea and even China say the rocket launches are aimed at developing inter-continental ballistic missiles.
North Korea s rocket launches
- February 2016: Launch of rocket reportedly carrying satellite
- May 2015: North Korea announces it has successfully tested a submarine-launched missile3 for the first time, but scepticism is then poured on the claim
- Dec 2012: North Korea launches three-stage rocket, says it successfully put a satellite into orbit; US defence officials confirm object in orbit
- Apr 2012: Three-stage rocket explodes just after take-off, falls into sea
- Apr 2009: Three-stage rocket launched; North Korea says it was a success, US says it failed and fell into the sea
- Jul 2006: North Korea test-fires a long-range Taepodong-2 missile; US said it failed shortly after take-off
Source By: BBC