As a result of the sanctions, the companies will not be able to do business with any other company or nation, though the real impact from the decision may remain symbolic.

Committee members also included a ban on the import and export of items on an internationally recognised list of sensitive technologies used to build missiles capable of delivering weapons of mass destruction.

North Korea said that its April 5 launch put a satellite into orbit that is broadcasting patriotic songs from the communist dynasty.

But no other nation has confirmed that the satellite was in orbit.

The US claims that North Korea fired a rocket over Japan as part of its programme to develop long-range ballistic missiles that could conceivably hit the US in the future.

A Security Council statement condemning North Korea's April 5 long-range rocket launch demanded tougher enforcement of financial sanctions and an arms embargo against Pyongyang.

The United States originally proposed that 11 North Korean firms be blacklisted.

Japan then added three more firms to that list, but the list was trimmed down to three due to objections from Russia, China and several other delegations, Security Council diplomats said.

John Sawers, Britain's UN ambassador, said the decision required all UN member states to freeze the assets of the three firms.