The rift between the US and Ukrainian presidents over Russia has continued, with White House officials accusing Volodymyr Zelensky of insulting Donald Trump. On Wednesday, Mr Zelensky rejected US demands for a share of its rare earth minerals - a "deal" Mr Trump said would reflect the amount of aid the US had provided to Ukraine during its war with Russia. On Thursday, a planned press conference with President Zelensky and the US Chief Envoy to Ukraine Keith Kellogg was cancelled. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Ukraine #US #BBCNews