America's National Security Adviser has said America should be “prepared” to take military action against North Korea.

Lieutenant General HR McMaster called on other world powers to prevent the rebellious regime from developing a nuclear arsenal, saying the state was acting in "open defiance of the international community".

Although he said the Trump administration would prefer to "work with others" to resolve the issue "short of military action", he said the US must be prepared for its armed forces to intervene.

“North Korea poses a grave threat to the United States, our great allies in the region, South Korea and Japan ... but also to China and others. And so it's important, I think, for all of us to confront this regime,” he said in an interview with Fox News.

“This regime that is pursuing the weaponisation of a missile with a nuclear weapon. And so this is something that we know we cannot tolerate ... The President has made clear that he is going to resolve this issue one way or another."

He added: “It may mean ratcheting up those sanctions even further and it also means being prepared for military operations if necessary."

President Donald Trump said on Saturday he would "not be happy" if North Korea carried out another missile test, adding that his Chinese counterpart President Xi Jinping would likely feel the same.

He refused to say whether this meant military action, saying: "I don't know, I mean, we'll see." He added: “We shouldn't be announcing all our moves. It is a chess game. I just don't want people to know what my thinking is.”

In pictures: North Korea military drill Show all 8 1 /8 In pictures: North Korea military drill In pictures: North Korea military drill North Korea's leader Kim Jong Un watches a military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video

Mr Trump also called the North Korean leader Kim Jong-Un “a pretty smart cookie” for being able to hang onto power after taking over the isolationist state at a young age.

On Saturday, a North Korean mid-range ballistic missile appeared to fail shortly after launch, the third such failure this month.