Japan also says it cannot find a signal, though admits it could take up to 24 hours to fully verify.

Japan, South Korea and several other nations believe the launch was nothing more than a cover for a long-range missile test.

The U.S. says this launch is a violation of the 2006 UN Security Council resolution that prohibits North Korea from testing any ballistic missiles.

In the next few days the five permanent members (US, Russia, China, the UK and France) and Japan will be meeting for consultations.

They'll be considering a draft resolution put forward by a number of Western countries. The proposal could toughen up the resolution passed by the UN in 2006.

China and Russia have resisted calls from the US for tougher sanctions on North Korea with both urging restraint.

The Russian Foreign Ministry said North Korea had informed Moscow ahead of time about the launch and Russian radars tracked it.

It is reported the Russian Foreign Minister Sergey Lavrov has been speaking with his counterparts including US Secretary of State Hillary Clinton.

Russia is a member of the six-party talks and it has been trying to get North Korea to give up its nuclear programme.

North Korea’s launch comes the same day as US President Barack Obama delivered a speech before the US-EU summit in Prague. He was speaking about reduction of nuclear arms and a nuclear-free world.

And when he learned about North Korea’s launch, his rhetoric became a little bit aggressive.

“Today’s missile launch by North Korea is stark evidence of how urgent this agenda is and how higher a priority it must be for all of us. We’ve called for a strong international response and I believe that we should start today by issuing a joint statement from this summit condemning North Korea’s provocative actions,” Barack Obama said.

Members of the international community are now rather cautious on the issue.

Earkier Washington, Tokyo and Seoul urged North Korea to halt the launch and restart international negotiations aimed at getting North Korea to abandon its nuclear program.

The Obama administration's senior envoy to North Korea, Stephen Bosworth, warned the country not to launch the multistage rocket as it goes against North Korea’s signals to resume nuclear disarmament talks.

Bosworth said then that he is prepared to go to Pyongyang whenever it is practical in order to restart international negotiations aimed at getting North Korea to abandon its nuclear program.