While it could not confirm the claims, the White House stated that the US would continue to "protect and defend" its allies in the region and "respond appropriately to any and all of North Korean provocations."
Leaders across the world have also responded to the news. The Japanese Prime Minister said the nation could not tolerate North Korea's nuclear testing, branding it a threat to Japan's security. The British Foreign Secretary Philip Hammond tweeted a response, saying the test would be a "grave breach of UN Security Council resolutions".