US President Joe Biden has authorised the use of US-supplied long-range missiles by Ukraine to strike even deeper inside Russia, the latest easing of limitations meant to prevent the conflict from further spiralling, according to one US official and three people familiar with the matter.

The decision allowing Ukraine to use the Army Tactical Missile System, or ATACMs, for attacks farther into Russia comes as thousands of North Korean troops have been sent into a region along Ukraine’s northern border to help Russia retake ground and as president-elect Donald Trump has said he would bring about a swift end to the war, expressing scepticism over continued support by the United States.
The weapons are likely to be used in response to the decision by North Korea to support Russian President Vladimir Putin’s invasion of Ukraine, according to one of the people.

The official and the people familiar with the matter were not authorised to discuss the decision publicly and spoke on condition of anonymity.

“The decision to allow Ukraine to strike inside Russia with US missiles is an unprecedented step leading to a third world war, but the response will be immediate,” Vladimir Dzhabarov, first deputy head of the Russian upper house’s international affairs committee, said on Sunday, according to Russia’s Tass news agency.

US President Joe Biden, right, and Ukraine’s President Volodymyr Zelensky during a meeting in the Oval Office at the White House in Washington in September. Photo: AP

US President Joe Biden, right, and Ukraine’s President Volodymyr Zelensky during a meeting in the Oval Office at the White House in Washington in September. Photo: AP

Poland was among the first to welcome the development.