President Donald Trump has suggested that he raised former Vice President Joe Biden and Biden’s son in a phone call with Ukraine’s new leader.
Democrats are pressing for investigations into whether Mr Trump improperly used his office to try to dig up damaging information about a political rival.
Mr Trump told reporters that the July 25 call with Ukrainian President Volodymyr Zelenskiy was “congratulatory” and focused on corruption in the East European nation.
In his remarks to reporters, he then raised Mr Biden as an example, although there is no evidence of wrongdoing by Mr Biden or his son Hunter, who was on the board of a Ukrainian gas company.
“It was largely the fact that we don’t want our people, like Vice President Biden and his son, creating to the corruption already in the Ukraine,” Mr Trump said as he left the White House for a trip to Texas.
Mr Biden, who is among the front-runners for the Democratic presidential nomination, accused Mr Trump of making a baseless political smear.
The matter has sparked a fierce debate over whether Mr Trump misused his office for political gain and whether his administration is withholding from Congress critical information about his actions.
The incident is part of a whistleblower complaint, but the acting director of national intelligence, Joseph Maguire, has refused to share details with politicians, citing presidential privilege.
Democratic House Speaker Nancy Pelosi, who has resisted calls for impeachment for other alleged Trump transgressions, said unless Mr Maguire provides information to Congress, administration officials “will be entering a grave new chapter of lawlessness which will take us into a whole new stage of investigation”.
A person familiar with the matter has told the Associated Press that Mr Trump urged Mr Zelenskiy to investigate Hunter Biden. The person was not authorised to discuss the issue publicly and spoke on condition of anonymity.
“Ukraine’s got a lot of problems,” Mr Trump said at the White House. “The new president is saying that he’s going to be able to rid the country of corruption and I said that would be a great thing. We had a great conversation. We had a conversation on many things.”
Hunter Biden was hired by the Ukrainian gas company Burisma Holdings in April 2014, two months after Ukraine’s Russia-friendly president was ousted by protesters and as his father was heavily involved in US efforts to support the new pro-Western government and its pledge to fight corruption.
The hiring of the younger Biden immediately raised concerns that the Ukrainian firm, whose owner was a political ally of the ousted president, was seeking to gain influence with the Obama administration.
Two years later, Joe Biden pressured the Ukrainian government to fire the prosecutor general, who was accused by many in Ukraine and in the West of being soft on corruption.
Mr Trump has claimed that the prosecutor, who had led an investigation into Burisma’s owner, “was after” Hunter Biden and the vice president was trying to protect his son. There is no evidence of this.
Mr Trump insisted he said “absolutely nothing wrong” in the call to Mr Zelenskiy.
After arriving in Texas, Mr Trump told reporters he will look into releasing details or a transcript of the call, but stressed that foreign leaders should feel free to speak frankly with an American president without fear that the details of their conversations will later be disclosed.
Mr Trump said if Ukraine released its own transcript it would be the same as his version of the call.
Mr Trump and Mr Zelenskiy plan to meet on the sidelines of the U.N. General Assembly later this week.