The official with direct knowledge of analysis of the incident conducted by American military and intelligence agencies, said that American and Japanese military ships and missile defences were fully operational and protecting land, sea and airspace on December 12.
But the launch was a surprise when it actually happened, he said.
According to CNN, the official stressed that the clues point to a concerted effort to deceive the US and its allies.
The analysis was ordered in the wake of the launch to determine what exactly happened and how much the US intelligence knew at the time, he said.
The official said one conclusion was that while missile defences can fully protect against a North Korean attack, the North Koreans have shown they can counter US measures to gather intelligence about what they are up to.
The most likely scenario, the official said, was that North Korea wasn't telling the truth when it announced several days before the launch that there were technical problems with the missile, the report said.
Washington: North Korea likely engaged in a deliberate campaign of deception before its long-range missile launch this month, catching the United States and its Asian allies ‘off guard’, an American official has said.
First Published: Friday, December 28, 2012, 15:41