Nikki Haley told an emergency meeting of the Council in New York that North Korean leader Kim Jong-un had shown through his actions that he was "begging for war".
"War is never something the United States wants," she said. "We don't want it now but our country's patience is not unlimited."
She urged the Security Council to take the "strongest possible measures" against North Korea after its sixth and largest nuclear test on Sunday.
"Only the strongest sanctions will enable us to resolve this problem through diplomacy," Haley said."We have kicked the can down the road long enough. There is no more road left."
Haley also said that countries which did business with Pyongyang are aiding their nuclear ambitions.
"The United States will look at every country that does business with North Korea as a country that is giving aid to their reckless and dangerous nuclear intentions," Haley said.
South Korea warns Pyongyang could fire more ICBM:
A day after North Korea’s sixth and largest nuclear test, South Korea has warned that Pyongyang could fire more Inter Continental Ballistic Missile (ICBM).
"We have continued to see signs of possibly more ballistic missile launches. We also forecast North Korea could fire an intercontinental ballistic missile," Jang Kyoung-soo, acting deputy minister of national defense policy, told a parliament hearing on Monday.
Earlier in July, North Korea had tested two ICBMs with an estimated range of 10,000 km (6,200 miles) which puts many parts of the United States within reach and prompting a new round of tough international sanctions.
South Korea also said that it was talking to the US about the deployment of aircraft carriers and strategic bombers to the Korean peninsula, reported the Reuters.