PRESIDENT Joe Biden has authorised the use of American long-range missiles by Ukraine to strike deep inside Russia, insiders have said.
The decision comes after Vladimir Putin launched "one of the largest" air attacks of the Ukraine war so far with 120 missiles and 90 drones.
After months of impasse, President Biden was last night said to have given Ukraine his blessing with just two months left in the White House.
Until now, Biden had been against any escalation that he believed would lead the United States and other NATO members into direct confrontation with Russia.
But the US leader may have changed his mind after North Korea sent thousands of troops to Russia to assist Moscow in reclaiming territory in the Kursk border region that Ukraine had taken this year.
The first deep strikes are likely to be carried out using the US' ATACMS rockets, which have a range of up to 190 miles.
Biden's latest move now marks a major US policy shift as he is about to leave office and President-elect Donald Trump has pledged to limit American support for Ukraine and end the war as soon as possible.
One of Trump's closest foreign policy advisers, Richard Grenell, criticised the decision on X.
Responding to the news, he wrote: "Escalating the wars before he leaves office."
The US weapons are likely to be used in response to North Korea's decision to send thousands of troops to Russia in support of Putin's invasion of Ukraine, three sources familiar with the matter said.
Biden hopes that this response will "send a message" to Kim Jong Un not to send any more of his men, according to the insiders.