The US military would use any capability it has to protect the American people if North Korea launched a missile at the United States, a senior US defense official said Thursday. The official, however, said the US missile defense system would not necessarily be used if North Korea launched a missile that was headed into an open ocean.

"If there is a test in which a missile goes up, for example, and it is headed into the ocean or whatever, would that be necessarily a trigger for our defensive systems? No, it wouldn't be," said the official, who spoke on condition of anonymity.

Asked if the United States would be obliged to use its missile defenses to try to shoot down a missile headed at its territory, the official replied: "Obviously the United States military would use any capabilities it had if it could protect the American people."

The official's comments were the strongest yet by a US defense official on whether the United States has activated its missile defense system and would use it against a potential North Korean launch.

Pentagon spokesmen have declined to comment on whether the missile defense system has been activated in the face of North Korean preparations for a launch of a long range Taepodong missile.

But the official's comments appeared aimed at countering speculation that the US missile defense system would be used against any North Korean launch, even one that did not directly threaten the United States.