"This is a way of like getting people to talk about [Kim]," Haley said in an interview with ABC News chief anchor George Stephanopoulos on "Good Morning America."
"It worked," Haley laughed. "Every other international community is now referring to him as 'Rocket Man.'"
The Kim regime has been making the world uneasy of late with its many missile launches this year.
In his speech to the U.N. General Assembly on Tuesday, Trump threatened to "totally destroy" North Korea if the U.S. is "forced to defend itself or its allies," prompting astonished gasps from the audience.
Haley said the president "was being honest" and that his bluntness was in fact "very much appreciated."
"I know that people and countries don't want to hear it," she said on "GMA" this morning. "If you want to talk about who's been giving the threats, it's certainly been the Kim regime."
The former South Carolina governor said the U.S. has "exhausted every diplomatic means" in trying to deal with North Korea, including dialogue and sanctions.
"And we are going to continue to do that. While he is being irresponsible, we're going to be responsible," Haley said. "The international community actually very much appreciated the blunt, honest approach that the president took on North Korea."