The U.S. government said it cannot verify North Korea's claim that it tested its underwater nuclear weapons system.

At a briefing Friday, U.S. National Security Council spokesperson John Kirby said the U.S. had no particular information about the supposed test, adding that the U.S. was not in a position to verify the North's claim.

He said the United States was in contact with the South Korean government to gather more information.

Kirby said North Korea's provocations were a constant problem, regardless of the veracity of the North's latest claim, and that the regime's pursuit of military expansion to threaten its neighbors and the region was hardly in doubt.

He said the North Korean threat was why U.S. President Joe Biden took "significant steps" to muster U.S. allies South Korea and Japan at the Camp David summit and that the United States has better information about the Korean Peninsula thanks to its discussions with its regional friends and the establishment of a new nuclear consulting group with South Korea.