Joe Biden has given Ukraine the green light to use US-supplied long-range missiles to strike targets within Russia for the first time.
The US president has signed off on the use of ATACMS rockets within the Kursk region, according to the New York Times.
His decision will raise expectations that Britain, the US and France could swiftly authorise Kyiv to use Storm Shadow missiles in the same way.
Volodymyr Zelensky, the Ukrainian president, has spent months urging Britain, the US and France to allow him to strike targets within Russia.
Sir Keir Starmer is known to be in favour, as is Emmanuel Macron, the French leader. But Mr Biden, who has a veto because the guidance chips in the rockets are US-made, has up until now been reluctant to go ahead.
Kursk, which borders Ukraine, has seen heavy fighting since Ukrainian troops took several towns in the region.
Mr Biden’s decision was said to be prompted by the arrival of North Korean troops in Kursk. Pyongyang is set to send as many as 100,000 soldiers, Bloomberg reported on Sunday.
Joe Biden, the US president, and Volodymyr Zelenskyy, the Ukrainian president, have disagreed over the use of weapons – Kevin Lamarque/Reuters
He was also responding to fears that Moscow’s assault force could dislodge Ukraine from its foothold inside Russian territory.
Kyiv has pleaded for the use of long-range missiles so it can target Russian supply lines and command centres, as well as airbases used to launch jets firing glide bombs at its troops.
Mr Biden earlier allowed Ukraine to fire the 50-mile Himars rockets over the border but had prevented the use of the 190-mile ATACMS missiles for fear of escalating the war.
