Biden has committed tens of billions of dollars to Kyiv's war effort, and at the weekend he reportedly ditched a long-standing red line on Ukraine's use of American weaponry to launch attacks deep into Russia. Donald Trump Jr tweeted that the president was trying to "get World War Three going" before his father took office.

The U.S. will allow Ukraine to use American-supplied longer-range weapons to conduct strikes inside Russian territory, a long-sought request by Kyiv. It was not clear if there would be limits on Ukraine's use of the Army Tactical Missile System,