North Korea has said the missile it tested overnight held a warhead capable of re-entering the earth’s atmosphere.
The claim was not proven and experts have cast doubt on the country’s ability to master such technology.
Kim Jong-un called the launch “impeccable” and a “breakthrough”. It was the first test from Pyongyang in more than two months, after a flurry earlier this year.
It has been condemned by the international community.
US President Donald Trump spoke to China’s President Xi Jinping by telephone, the White House said, urging him to “use all available levers to convince North Korea to end its provocations and return to the path of denuclearisation”.
Mr Xi responded by telling Mr Trump it was Beijing’s “unswerving goal to maintain peace and stability in north-east Asia and denuclearise the Korean peninsula,” Chinese news agency Xinhua reported.
China is North Korea’s biggest ally and most important trading partner, and the two share a land border.
Experts say the height reached by the inter-continental ballistic missile (ICBM) indicates Washington could be within range, although North Korea is yet to prove it has reached its aim of miniaturising a nuclear warhead.
White House spokeswoman Sarah Sanders said the US would put more sanctions on North Korea “very shortly”.