US President Joe Biden has brushed off a threat from Russia’s leader Vladimir Putin about a war with the West if Ukraine’s allies allow it to use weapons to strike targets deeper inside Russia. It’s a shift that Kyiv has been pressing for for weeks but no decision was immediately announced following a meeting between Biden and Britain’s prime minister, Keir Starmer. “The United States is committed…to help Ukraine as a defence against Russia’s onslaught of aggression. Make it clear that Putin will not prevail in this war. The people of Ukraine will prevail,” said Biden, without making any ref…