North Korea in December launched a range rocket to orbit a satellite. Launches in 2006 and 2009 coincided with North Korean nuclear tests and satellite imagery from January indicates preparations are under way for a third test at a nuclear facility.
South Korea President-elect Park Geun-hye, who is to be sworn on Feb. 25, said Thursday that North Korea was increasingly out of step with the international community.
"North Korea cannot achieve anything with nuclear (threats)," she was quoted by China's official Xinhua news agency as saying. "If the North presses ahead with a nuclear test despite the warning from the international community, it will bring further isolation."
North Korea said any nuclear test would be part of its anti-U.S. policies.
Victoria Nuland, a spokeswoman for the U.S. State Department, said Washington was committed to existing resolutions at the U.N. Security Council censuring North Korea.
"If provocations continue, there will be continued consequences," she said during her regular press briefing.