As North Korea crows about the successful test of what it says is a "breakthrough" intercontinental ballistic missile, US President Donald Trump has appealed to China to rein in its ally.

Trump, who has vowed to halt North Korea's nuclear and missile programs, spoke with Chinese President Xi Jinping within hours and said additional major sanctions would now be imposed on North Korea.

"Just spoke to President Xi Jinping of China concerning the provocative actions of North Korea. Additional major sanctions will be imposed on North Korea today. This situation will be handled!" Trump wrote on Twitter on Wednesday. He gave no other details about the sanctions.

The UN Security Council is scheduled to meet on Wednesday to discuss the launch.

The latest missile test was the highest and longest any North Korean missile had flown, landing in the sea near Japan, with North Korea saying it puts the US mainland within range of its nuclear weapons.

North Korea said the new missile reached an altitude of about 4475km, more than 10 times the height of the International Space Station, and flew 950km during its 53-minute flight.

"After watching the successful launch of the new type ICBM Hwasong-15, (leader) Kim Jong Un declared with pride that now we have finally realised the great historic cause of completing the state nuclear force, the cause of building a rocket power," according to a statement read by a television presenter.

US, Japanese and South Korean officials all agreed the missile, which landed within Japan's exclusive economic zone, was likely an ICBM. The test itself did not pose a threat to the United States, its territories or allies, the Pentagon said.

"It went higher, frankly, than any previous shot they've taken, a research and development effort on their part to continue building ballistic missiles that can threaten everywhere in the world, basically," US Defense Secretary Jim Mattis told reporters at the White House.

Trump also spoke by phone with Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-In, with all three reaffirming their commitment to combat the North Korean threat.

"It is a situation that we will handle," Trump told reporters.

Trump, who was briefed on the missile while it was in flight, said it did not change his administration's approach to North Korea, which has included new curbs to hurt trade between China and North Korea.

"Diplomatic options remain viable and open, for now," US Secretary of State Rex Tillerson said.
China, North Korea's lone major ally, expressed "grave concern" at the test, while calling for all sides to act cautiously.