The Kremlin warns Kyiv's use of such missiles would mark an escalation in the conflict, hours after Joe Biden gives the green light.

Ukraine has been pleading with the US for months to let it use American-made weapons to hit military targets inside Russia beyond the border zone. Now, as he nears the end of his presidency, Joe Biden has relented and decided to lift some restrictions,

The U.S. decision to authorise long-range Ukrainian strikes could help Kyiv defend the foothold in Russia's Kursk region that it seized as leverage in any war talks, but may come too late to change the course of the war,