The United States cautioned the North Korean leadership that it would "utterly destroyed" if war were to break out, after Pyongyang test-fired its most innovative intercontinental ballistic missile, setting the U.S. mainland range.
The Trump administration has stated all options were on the desk in dealing with North Korea, such as military ones, but has stated it still favors a diplomatic option.
At the U.N. Security Council meeting, Nikki Haley, U.S. ambassador, warned: "If war comes, the U.S. will utterly destroy the North Korean regime."
Haley said the United States has asked China to cut off oil supply to North Korea. U.S. President Donald Trump, who's vowed to halt North Korea's nuclear and missile programs, spoke with Chinese President Xi Jinping before on Wednesday.
China is the only significant ally of North Korea, and they share trade that is significant and a long border.
"We've not sought war with North Korea, and still today we don't seek it. If war does come, it is going to be because of continued acts of aggression as we seen yesterday," Haley said.
North Korea said the new missile soared to an altitude of approximately 4,475 kilometers (2,780 miles) - over ten times the height of the International Space Station - and flew 950 kilometers (590 miles) during its 53-minute flight.
It flew higher and more before, landing from the sea near Japan. Experts said the new "Hwasong-15" missile liberally gave North Korea the ability to hit the USA, such as the East Coast, even though it wasn't clear whether it would take a nuclear weapon.
North Korea, which ran its sixth and biggest nuclear bomb test in September, has analyzed dozens of ballistic missiles in defiance of sanctions under Kim's leadership.