The United States has warned North Korea that it will take punitive action if the communist state conducts any nuclear tests.
"A weapons test would be a very serious development. It would be something where the North Koreans would be defying not only us, but our partners in the six-party talks, and action would have to be taken," US National Security Adviser, Stephen Hadley said, speaking to US television networks on Sunday.
He, however, did not specify what the US exactly planned to do.
"We've seen some evidence that says that they may be preparing for a nuclear test," Hadley said.
He, however, admitted that North Korea is a 'hard target and that correctly assessing its intentions is nearly impossible'.
Analysts and media reports noted that this is first time that a senior Bush administration official has warned North Korea of punitive action if it crosses the line.
Hadley said Washington was sharing information with China, South Korea, Russia and Japan -- the other countries trying to engage North Korea in the six-party talks.
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