Former US Secretary of State Hillary Clinton accused President Trump of putting his personal and political gain ahead of the national interest.
In a speech at Georgetown University in Washington, she described his phone call with the Ukrainian leader as a “cheap extortion racket”.
Mr Trump faces impeachment proceedings for urging Ukraine to investigate Joe Biden, his main rival for the presidency. The president has dismissed them as a “witch hunt”.
Hillary Clinton condemns Trump’s ‘cheap extortion racket’