US Ambassador to the United Nations Nikki Haley says there is no point in having an emergency session of the United Nations Security Council if it produces nothing of consequence.
"An additional Security Council resolution that does not significantly increase the international pressure on North Korea is of no value," She said in a statement on Sunday.
"In fact, it is worse than nothing, because it sends the message to the North Korean dictator that the international community is unwilling to seriously challenge him. China must decide whether it is finally willing to take this vital step.
Earlier Hayley tweeted: "Done talking about NKorea.China is aware they must act.Japan & SKorea must inc pressure.Not only a US problem.It will req an intl solution."
The tough stance comes after the United States flew two supersonic B-1B bombers over the Korean peninsula in a show of force, in response to what North Korea said was a successful test of an intercontinental ballistic missiles (ICBM) on Friday.
China, the North's main ally, said it opposed North Korea's missile launches, which it said violate UN Security Council resolutions designed to curb Pyongyang's banned nuclear and missile programmes.
Early in his presidency, US President Donald Trump met with Chinese President Xi Jinping and had expressed hope Beijing would use its economic clout to curb North Korea's nuclear ambitions.
But on Saturday, Trump said on Twitter that he was "very disappointed in China" which he said profits from trade with the United States but does "NOTHING for us with North Korea, just talk. We will no longer allow this to continue," he said.
North Korean leader Kim Jong Un personally supervised the midnight test launch of the missile on Friday night and said it was a "stern warning" for the United States that it would not be safe from destruction if it tries to attack, the North's official KCNA news agency said.
North Korea's state television broadcast pictures of the launch, showing the missile lifting off in a fiery blast in darkness and Kim cheering with military aides.
The missile test came a day after the US Senate approved a package of sanctions against North Korea, Russia and Iran.
Also on Sunday, the US Missile Defense Agency announced the United States had successfully shot down a medium-range missile in the latest test of its THAAD missile defence program which is designed to protect the country against potential threats from countries such as North Korea and Iran.
The test was planned well before the rising tensions with North Korea and involved a medium-range missile, not the long-range types being tested by the North Koreans.
