Nikki Haley: Trump's fire and fury comment 'not an empty threat'

US ambassador to the United Nations Nikki Haley said President Donald Trump's "fire and fury" comment last month about North Korea's nuclear program was not an empty threat.

In an interview that aired Sunday with CNN's Dana Bash on "State of the Union," Haley emphasized that Defense Secretary James Mattis has an array of options to destroy the nation of some 25 million people.

If the US exhausts diplomatic options on North Korea, the US military would "take care of it," Haley said,

"We wanted to be responsible and go through all diplomatic means to get their attention first," Haley said. "If that doesn't work, General Mattis will take care of it."

Haley warned a war would mean the destruction of North Korea.

"If North Korea keeps on with this reckless behavior, if the United States has to defend itself or defend its allies in any way, North Korea will be destroyed," Haley said. "And we all know that, and none of us want that."

The United Nations Security Council adopted a new round of sanctions on North Korea last Monday in response to the nation's sixth and largest nuclear weapons test.

Trump called the move "another very small step," but Haley talked up the significance of the agreement and went on to say it was near the limit of what the US could accomplish through the UN.

"We have pretty much exhausted all the things that we could do at the Security Council at this point," she said.

London

On Friday, Trump responded to a terrorist attack on the London Underground by taking to Twitter, quickly saying the perpetrators were "in the sights of Scotland Yard" and prescribing an expansion of his travel ban as well as moves aimed at shutting down terrorist recruitment on the internet.

UK Prime Minister Theresa May responded to the comments in an interview on ABC's "This Week."

"I don't think it's helpful for anyone to speculate on what is an ongoing investigation," May said.

In her interview on CNN, Haley said Trump would not want to harm an investigation but was "emotional and passionate" about what happened in the UK.

"There was no ill intent with that," Haley said. "I think it was the fact that he was just very concerned and very disturbed that these terrorist attacks keep happening in Great Britain."