Donald Trump has threatened to halt weapons supplies to Ukraine unless Kyiv ends its long-range strikes on Russian energy infrastructure.The White House made it clear to European officials over the weekend that a scheme allowing Ukraine's allies to buy US arms and give them to Kyiv could be suspended.Mr Trump is said to be angry at Volodymyr Zelensky's continued strikes on Russian oil refineries, and according to officials in Europe, the US administration has also threatened to withhold intelligence from Ukraine.