U.S. President Donald Trump said Sunday he did nothing wrong in a telephone conversation with the new president of Ukraine amid news report that Trump allegedly urged him to investigate the son of former vice president and 2020 Democratic presidential hopeful Joe Biden.

Speaking to reporters, Trump described his phone call with President Volodymyr Zelensky as “absolutely perfect.”

“The conversation I had was largely congratulatory, was largely corruption, all of the corruption taking place. 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,” Trump said.

According to news reports, Trump urged Zelensky about eight times during their conversation to investigate Biden’s son. Sources were quoted saying Trump’s intent was to get Zelensky to collaborate with Trump lawyer Rudolph Giuliani on an investigation that could undermine Biden.

Ukrainian Foreign Minister Vadym Prystaiko on Saturday denied Trump had pressured Zelensky during the call, telling the media outlet Hromadski that Ukraine would not take sides in U.S. politics even if the country was in a position to do so.

Trump and Guiliani have pushed for an investigation of the Bidens for weeks, following news reports this year that explored whether a Ukrainian energy company tried to secure influence in the U.S. by employing Biden’s younger son, Hunter.

Democrats are condemning what they perceive as a concerted effort to damage Biden, who has been thrust into the middle of an unidentified whistleblower’s complaint against Trump. Biden is currently the leading candidate for the Democratic presidential nomination.

The Trump administration has blocked procedures under which the whistleblower complaint would have normally been forwarded by the U.S. intelligence community to members of the Democrat-controlled Congress, keeping its contents secret.

Biden said late Friday that if the reports are accurate, “then there is truly no bottom to President Trump’s willingness to abuse his power and abase our country.” Biden also called on Trump to disclose the transcript of his conversation with Zelensky so “the American people can judge for themselves.”

When asked about releasing the transcript,  Secretary of State Mike Pompeo told ABC News that  “those are private conversations between world leaders and it wouldn’t be appropriate to do so except in the most extreme circumstances.”

The intelligence community inspector general has described the whistleblower’s August 12 complaint as “serious” and “urgent,” conditions that would normally require him to forward the complaint to Congress. Trump has characterized the complaint as “just another political hack job.”