The US media reported that an unidentified intelligence official filed the whistleblower complaint in August, alleging that Trump communicated with a foreign leader and made an unspecified "promise". The complaint was filed with the inspector general for the intelligence community, an independent watchdog, Xinhua news agency reported.
"If these reports are true, then there is truly no bottom to President Trump's willingness to abuse his power and abase our country," Biden, the former US Vice President, said in a statement released on Friday.
"This behaviour is particularly abhorrent because it exploits the foreign policy of our country and undermines our national security for political purposes," Biden said.
At least part of the complaint involved Ukraine, The Washington Post and The New York Times both reported.
House Democrats have been probing a July phone call between Trump and Ukrainian President Volodymyr Zelensky to see whether the former and his attorney Rudolph Giuliani sought to manipulate Kiev into helping his re-election campaign.
The Wall Street Journal, in an exclusive report on Friday, said that Trump had urged Zelensky roughly eight times in the phone call to work with Giuliani in seeking information about Biden's son, Hunter, that could be damaging to the former Vice President's campaign.
Meanwhile, Giuliani defended the possibility of Trump urging Zelensky to scrutinize Biden, tweeting on Thursday that "a President telling a Pres-elect of a well known corrupt country he better investigate corruption that affects US is doing his job".
Biden, for his part, lashed out at the assertions alleging his wrongdoing concerning Ukraine.
"Not one single credible outlet has given any credibility to these assertions. Not one single one," he was quoted by the Post as saying after a campaign event on Friday.
Acting Director of National Intelligence (DNI) Joseph Maguire has been withholding the whistleblower complaint from the Congress.
House Speaker Nancy Pelosi urged the release of the whistleblower complaint on Friday. "The President and Acting (DNI's) stonewalling must end immediately, and the whistleblower must be provided with every protection guaranteed by the law to defend the integrity of our government and ensure accountability and trust", she said in a statement.
( With inputs from IANS )