The US will launch a “massive military response” to any threats from North Korea, Pentagon Chief James Mattis has said, after the Asian country conducted its most powerful nuclear test yet.

James Mattis’ strong warning came just hours after North Korea carried out its sixth nuclear test – the most powerful blast to date.

“Any threat to the United States or its territories, including Guam, or our allies will be met with a massive military response, a response both effective and overwhelming,” Mattis said on Sunday.

“We are not looking to the total annihilation of a country, namely North Korea, but as I said, we have many options to do so.”

The official Korean Central News Agency (KCNA) said the hydrogen bomb test on Sunday morning, ordered by leader Kim Jong-un, was a “perfect success”.

It was North Korea’s first nuclear test since Donald Trump took office, and marked a direct challenge to the US president, who hours earlier talked by phone with Shinzo Abe, Japan’s prime minister, about the “escalating” nuclear crisis in the region.

Trump also warned on Sunday that the time for “appeasement” was over and threatened drastic economic sanctions.

When asked if he would attack the North, Trump said, “we’ll see”.