China and other world powers will back "further consequences" against North Korea if it undertakes new provocation following its rocket launch, US Secretary of State Hillary Clinton said Monday.

Japan and other countries that have negotiated with North Korea in a bid to scrap its nuclear weapons program have expressed fears that Pyongyang may carry out a nuclear weapons test following the failed rocket launch last week.

"We have all agreed -- that includes China -- that there will be further consequences if they pursue another provocative action," Clinton told reporters when asked if China would press North Korea to avoid a nuclear test.

China is believed to have the most influence with North Korea among the parties to the moribund six-party negotiations aimed at dismantling North Korea's nuclear weapons program.

Besides China and North Korea, the other countries are the United States, Russia, Japan and South Korea.

"We are working to ensure that the new North Korea leadership hears unequivocally from the international community that their provocative behavior will not be rewarded," Clinton said during a trip to Brasilia.

She said the United Nations is sending a clear message to the North Koreans that their will be "consequences" for their behavior.

The UN Security Council on ordered tightened sanctions on North Korea over its failed rocket launch -- which the West called a disguised missile test -- and warned of new action if the isolated state stages a nuclear test.

Japanese and South Korean analysts and officials say satellite imagery showing what preparations at the North Korean town of Punggye-ri -- where nuclear blasts were staged in 2006 and 2009 -- suggest a test could be imminent.

Clinton expressed hope that Kim Jong-Un, who succeeded his father Kim Jong-Il following his death in December, would still set North Korea on a new path despite having ordered the missile launch.

"The new young leadership of North Korea has a very stark choice," Clinton said at a press conference with Brazilian Foreign Minister Antonio Patriota.

"They need to take a hard look at their policies, stop the provocative action, open to the rest of the world, work to educate their people, feed their people, put their people first ahead of their ambitions to be a nuclear power and rejoin the international community," she said.