The White House challenged North Korea’s claim that it has tested a hydrogen bomb, as the latest nuclear test thrust the reclusive nation back into the spotlight.

White House press secretary Josh Earnest said Wednesday the U.S. analysis so far shows the test was “not consistent” with a hydrogen bomb. He said the U.S. assessment is ongoing and not yet complete.

Mr. Earnest said the administration is still determining how to respond, adding that Susan Rice, Mr. Obama’s national security advisor, spoke Wednesday with the Chinese ambassador to the U.S. to discuss the issue, he said. “There’s no denying the significant role China would play in all of this,” Mr. Earnest said.

… The test may push the U.S. to refocus on North Korea. “This has demonstrated to everyone that the U.S. has to stay active in Asia—that there are big problems here that aren’t all about U.S.-China competition,” said Richard Bitzinger, a security expert at the S. Rajaratnam School of International Studies in Singapore.