Former US vice president Joe Biden has decried reports that President Donald Trump urged the president of Ukraine to look into his son’s business dealings there.
Mr Biden said that if the reports are true, “then there is truly no bottom to President Trump’s willingness to abuse his power and abase our country”.
The 2020 Democratic presidential candidate said Mr Trump should release the transcript of his July phone conversation with President Volodymyr Zelenskiy “so that the American people can judge for themselves”.
Mr Biden released the statement after news organisations reported that Mr Trump had urged Mr Zelenskiy to probe the activities of Mr Biden’s son Hunter, who worked for a Ukrainian gas company.
The Democratic front-runner’s campaign later sent out a fundraising letter urging potential donors, “Don’t let the President get away with this gross abuse of power”.
Mr Trump said there was nothing inappropriate in his contacts with foreign leaders.
At least two of Biden’s rivals called on fellow Democrats in the House of Representatives to push forward on impeachment of Mr Trump.
Despite multiple congressional investigations into the president, House Speaker Nancy Pelosi has resisted calls for impeachment from many members of her caucus, arguing such a step would be divisive and could backfire against the party in 2020.
Massachusetts senator Elizabeth Warren said that posture makes Congress complicit in Mr Trump’s outreach to Ukraine.
“A president is sitting in the Oval Office, right now, who continues to commit crimes,” Ms Warren tweeted. “He continues because he knows his Justice Department won’t act and believes Congress won’t either. Today’s news confirmed he thinks he’s above the law. If we do nothing, he’ll be right.”
Julian Castro, the former housing secretary, said Mr Trump needs to be impeached.
“I love these House Democrats — my brother is one of them,” he said. “But it’s time for them to do something. It’s time for them to act.” Mr Castro’s brother Joaquin represents Texas in the House.
New Jersey senator Cory Booker did not call for impeachment but said the allegations were “sobering and serious stuff” that should be “rocking Washington right now”. He declined to call them treason.
“I want to see this investigated,” he said. “What we know already, if it is true, constitutes at the very least serious misconduct.”