US Ambassador to the UN Nikki Haley, the first Indian-American to hold a cabinet rank, pledged that the US plans to "tighten the screws" on North Korea's nuclear ambitions.
"We are going to send a very strong, unified message to North Korea," Haley said on Tuesday.
Haley's comments at the UN, alongside ambassadors from Japan and South Korea, came days after North Korea tested another ballistic missile.
In her remarks, Hailey warned nations around the world not to economically assist the nation, CNN reported.
"If you are supporting North Korea, you are against the rest of the international community," Haley said.
Haley said the international community wants to be able to support North Korea, but as long as it continues trying to grow its nuclear programme with missile tests, North Korea would remain an "island".
Haley said a plan is still in the works between the US, Japan, South Korea and China -- North Korea's only major ostensible ally -- to halt North Korea's progress on nuclear weapons and ballistic missiles.
Any country that did not look at putting new sanctions on North Korea was, in effect, helping the isolated nation, she said.
Haley also criticised Moscow, after Russian President Vladimir Putin responded to North Korea's latest missile launch by saying that while his country opposed Pyongyang's nuclear programme, it was unacceptable for countries to intimidate North Korea.
"What about North Korea intimidating us?" Haley said, adding that Russia had it "all wrong".
When asked what the US would do if it was confirmed that North Korea had been behind the major ransomware attack plaguing computer systems across the globe, Haley said: "Sadly, it wouldn't be a surprise".