The British Foreign Office said it had summoned the North Korean ambassador to condemn Wednesday’s ballistic missile test.
North Korea said it had successfully tested a new intercontinental ballistic missile in a “breakthrough” that put the U.S. mainland within range of its nuclear weapons.
“I summoned the North Korean Ambassador to the Foreign Office to make clear to him our condemnation of this latest ballistic missile test,” Minister for Asia and Pacific Mark Field said in a statement.
“North Korea claims it wants to bring security and prosperity to its people. But its actions are creating only insecurity and deepening its isolation,” said Field.
Britain is a permanent member of the UN Security Council.
The latest test was the highest and longest any North Korean missile had flown, and it landed in the sea near Japan.
Trump, who has vowed to halt North Korea’s nuclear and missile programmes, spoke with Chinese President Xi Jinping on Wednesday and urged Beijing to rein in its ally North Korea.
North Korea said the new missile reached an altitude of about 4,475 km (2,780 miles) – more than 10 times the height of the International Space Station – and flew 950 km (590 miles) during its 53-minute flight.
Experts said the new “Hwasong-15” missile theoretically gave North Korea the ability to hit the U.S. mainland, including the East Coast, although it was not clear whether it could carry a nuclear weapon.
North Korea, which conducted its largest nuclear bomb test in September, has tested dozens of ballistic missiles under its leader, Kim Jong Un, in defiance of international sanctions.
Previous U.S. administrations have failed to stop North Korea from developing nuclear weapons and a sophisticated missile programme.
Trump has also struggled to contain Pyongyang since he came to office in January.
The Republican president on Wednesday again urged China to use its leverage on North Korea and promised more sanctions against the country, two strategies that have borne little fruit so far.
“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.
China, the North’s sole major ally, has so far refrained from taking some of the most drastic steps against North Korea, such as imposing an oil embargo.
White House spokeswoman, Sarah Sanders said the U.S. sanctions would come very soon and would add “maximum pressure on North Korea.”
Kim personally guided the test and said the new launcher was “impeccable”, state media said.
He described the new vehicle as a “breakthrough”.
North Korea also described itself as a “responsible nuclear power”, saying its strategic weapons were developed to defend itself from “the U.S. imperialists’ nuclear blackmail policy and nuclear threat”.
U.S., Japanese and South Korean officials all agreed the missile, which landed within Japan’s exclusive economic zone, was likely an ICBM.