The United States is skeptical of North Korea's claimed development of its own nuclear fusion technology.

State Department spokesman Philip Crowley said during a regular briefing that the U.S. won't dissuade people from those who are skeptical about Pyongyang's claim.

He said North Korea has, at times, made such claims and that Washington will continue to closely monitor the situation for any developments.

The North said Wednesday that its scientists succeeded in creating a nuclear fusion reaction.