The US president, Joe Biden, has publicly apologised to the Ukrainian president, Volodymyr Zelenskiy, for the months of delay in American military assistance that allowed Russia to make gains on the battlefield, and announced a further $225m (£177m) in military aid to Ukraine. Meeting Zelenskiy in Paris on Friday, Biden told him: “You haven’t bowed down, you haven’t yielded at all, you continue to fight in a way that is … just remarkable. We are not going to walk away from you.” Biden said: “I apologise for those weeks of not knowing” what was going to happen in terms of...