WASHINGTON (AP) — President Barack Obama on Wednesday reaffirmed the U.S. commitment to the security of its Asian allies in discussions with the leaders of South Korea and Japan about North Korea's claim that it had tested a hydrogen bomb.

The White House says Obama, South Korean President Park Geun-Hye and Japanese Prime Minister Shinzo Abe agreed that North Korea's actions "constitute yet another violation of its obligations and commitments under international law."

In separate conversations Wednesday evening, Obama and the two Asian leaders "agreed to work together to forge a united and strong international response to North Korea's latest reckless behavior," the White House said.

Secretary of State John Kerry held similar conversations Wednesday with the foreign ministers of South Korea and Japan, the State Department said.

Pyongyang's announcement of a successful hydrogen bomb test would mark a major and unanticipated advance for its still-limited nuclear arsenal. White House spokesman Josh Earnest questioned that claim earlier Wednesday, saying the U.S. government's initial analysis of underground activity in North Korea "is not consistent with the claims that the regime has made of a successful hydrogen bomb test."

"We're obviously going to continue to look at this by monitoring the situation, assessing the available data and evidence," Earnest said.