Former Vice President Joe Biden again called for President Donald Trump to release the transcript of his July phone call with Ukrainian president Volodymyr Zelensky amid reports that Trump pressured Zelensky to investigate Biden.

Trump tweeted Monday that the media "says I 'pressured the Ukrainian President at least 8 times during my telephone call with him.' This supposedly comes from a so-called "whistleblower" who they say doesn’t even have a first hand account of what was said."

Biden's account responded: "So release the transcript of the call then.”

At issue are two developments that have come to a head in the last week.

Trump's tweet is a reference to a Wall Street Journal report that stated Trump repeatedly pressured Zelensky to investigate Hunter Biden, the former vice president's son, and to work with his personal attorney, Rudy Giuliani, on the matter.

That phone call is reportedly the subject of a whistleblower complaint by a U.S. intelligence official, according to both the Washington Post and The New York Times.

Lawmakers are separately investigating whether Trump pushed for Zelensky to probe Biden's family's dealings in his country.

On Sunday, Trump confirmed that he discussed Biden during a phone call on July 25 with Zelensky, saying the "The conversation I had was largely congratulatory."

However, during a meeting Monday at the United Nations, Trump claimed that he, "didn’t do it” and that he hoped people would see a transcript of the call because they would be “very disappointed.”

“We’ll make a determination about how to release it, releasing it, saying what we said,” Trump also said Sunday, while defending his conversation as “perfect.”

Biden told reporters on Saturday, “He’s doing this because he knows I’ll beat him like a drum. And he’s using an abuse of power and every element of the presidency to try to smear me."

The president's personal attorney Rudy Giuliani has previously raised questions about whether Biden, as vice president, pushed for the ouster of former Ukrainian prosecutor general Viktor Shokin, who had investigated a private Ukrainian gas company, Burisma Group. Hunter Biden was a board member of Burisma.

But Ukraine's current prosecutor, Yuriy Lutsenko, told Bloomberg News Service in May that "Hunter Biden did not violate any Ukrainian laws — at least as of now, we do not see any wrongdoing.”

Biden has previously said he wanted Shokin out as prosecutor general because he wasn’t doing enough to investigate corruption. The former vice president in March 2016 called on Ukraine’s Parliament to dismiss Shokin, or the United States would withhold $1 billion in loan guarantees, according to the New York Times. Shokin was eventually voted out by parliament, but no evidence showing Biden intentionally tried to benefit his son has surfaced.

Some moderate Republicans and Democrats have raised the alarm over the reports that Trump pressured the Ukrainian leader to investigate his political rival.

Republican Sen. Mitt Romney said Sunday that it "would be troubling in the extreme" in a tweet if Trump pressured Zelensky to investigate Biden.

"At this point, the bigger national scandal isn’t the president’s lawbreaking behavior," Rep. Alexandria Ocasio-Cortez tweeted Sunday, "it is the Democratic Party’s refusal to impeach him for it."

Contributing: John Fritze, Bart Jansen, Nicholas Wu, David Jackson, Michael Collins, Deirdre Shesgreen.