Some U.S. officials say that the explosive force of North Korea's claimed nuclear test may have been as small as two-hundred tons.

Amid questions about the test's authenticity, the officials speaking on condition of anonymity said seismic data analyses show that its size may have stopped short of two-hundred tons. This would make it similar in size to a detonation of conventional explosives.

It would also make it smaller than a normal nuclear test and earlier U.S. forecasts of a several hundred ton to a kiloton explosion.

However, Reuters and The Associated Press quoted the officials as also saying that it's unlikely Pyongyang faked a nuclear test, adding weight to the theory that a nuclear test was conducted but not successfully.

U.S. Defense Department spokesman Bryan Whitman again on Wednesday said data analysis was ongoing without saying when confirmation will come.