US President Donald Trump's tweet about having a bigger nuclear button than North Korean leader Kim Jong-un has kept Kim "on his toes" and makes clear the risks of a nuclear standoff, UN Ambassador to the United Nations Nikki Haley says.
After Mr Kim asserted that he had a nuclear button at the ready, Mr Trump last week dismissed the taunt by saying in a tweet that the US button at his disposal was bigger and more powerful.
- No, Donald Trump does not have a nuclear button
- Donald Trump brags of having a 'bigger button' than Kim Jong-un
The comment drew criticism, including from former Vice President Joe Biden, who said it caused allies to lose confidence in Washington.
Asked on US television whether the President's tweet was a good idea, Ms Haley said: "I think that [Mr Trump] always has to keep Kim on his toes.
"It's very important that we don't ever let him get so arrogant that he doesn't realise the reality of what would happen if he started a nuclear war," she told ABC's This Week.
Ms Haley said North Korea should be clear that the United States will not reduce pressure on Mr Kim.
"We're not going to let them go and dramatise the fact that they have a button right on their desk and they can destroy America," she said. "We want to always remind them we can destroy you too, so be very cautious and careful with your words and what you do."