The information was revealed by US officials to the New York Times. The source said that the long-range missiles provided by the US could be used to protect Ukrainian forces in the Kursk province, western Russia.
This decision by President Joe Biden is a major change in US policy 2 months before President-elect Donald Trump takes office.
US officials said allowing Ukraine to use the long-range ATACMS missile was in response to Russia's surprise decision to bring North Korean troops into the war.
Ukrainian President Volodymyr Zelensky did not confirm that the US had given him permission to use long-range missiles to attack Russia, but on November 17 he stressed that it was more important to lift restrictions on the number of missiles used to attack Russia.
Mr Biden began easing restrictions on the use of US-supplied weapons on Russian soil after Russia launched a cross-border offensive in May towards Kharkiv, Ukraine’s second-largest city.
At that time, Mr. Biden allowed Ukraine to use the HIMARS system, which has a range of about 80 kilometers, against Russian forces. However, Mr. Biden did not allow Ukraine to use the longer-range ATACMS, which has a range of about 290 kilometers, to defend Kharkiv.
US officials do not expect any change in the situation of the war in Ukraine with this latest move, but the goal of the adjustment is to send a message to North Korea not to send more troops to Russia.
Officials note that, after Ukraine was able to use missiles against Russian and North Korean troops threatening Ukrainian forces in Kursk, Biden could also allow Ukraine to use the weapons elsewhere.
