US president Donald Trump repeatedly prodded Ukraine’s president to look into Democratic rival Joe Biden, according to a rough transcript summarising a call between the two leaders.

In the July 25 call, Mr Trump raised unsubstantiated allegations that the former vice president sought to interfere with a Ukrainian prosecutor’s investigation of his son Hunter.

According to the memo, Mr Trump said to Ukrainian president Volodymyr Zelenskiy: “I heard you had a prosecutor who was very good and he was shut down and that’s really unfair.

“A lot of people are talking about that, the way they shut your very good prosecutor down and you had some very bad people involved.”

He continued: “The other thing, there’s a lot of talk about Biden’s son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the (US) Attorney General would be great.

“Biden went around bragging that he stopped the prosecution so if you can look into it… It sounds horrible to me.”

Mr Zelenskiy said in response: “The issue of the investigation of the case is actually the issue of making sure to restore the honesty so we will take care of that and will work on the investigation of the case.”

“On top of that, I would kindly ask you if you have any additional information you can provide us, it would be very helpful.”

The release of the rough transcript set the parameters of the political debate to come, with Mr Trump dismissing it as routine and Democrats saying it laid the ground for an impeachment inquiry.

Mr Trump aides believed that his oblique, message-by-suggestion style of speaking would not lend itself to the discovery of a “smoking gun” in the transcript.

At a news conference at the UN general assembly, Mr Trump said the diplomacy he conducted this week is being overshadowed by the controversy.

He said he met nearly 20 different world leaders during three days in New York and signed a partial trade agreement with Japan.

But he said that, instead of covering those topics, journalists choose to waste their time covering “nonsense”.

Mr Zelinsky has said no one “pushed” him to investigate the Bidens while Mr Trump said there was “no push, no pressure, no nothing”.

Trump Intelligence Whistleblower Memo
Page four of five from a rough transcript of President Donald Trump’s July 25 telephone conversation with Ukraine’s newly elected president Volodymyr Zelenskiy (The White House via AP)

Mr Trump has recently confirmed that he ordered the freezing of nearly 400 million dollars in aid to Ukraine a few days before the controversial phone call.

It was not clear from the summary whether Mr Zelenskiy was aware that Mr Trump had frozen the aid.

The president has insisted he did nothing wrong and has denied that any request for help in procuring damaging information about Mr Biden was tied to the aid freeze.

The president took the 30-minute call from the White House residence, while officials in the Situation Room listened in and worked to keep a record of the conversation, as is standard practice.

The resulting memorandum was classified as “Secret’ and “ORCON, for “originator controlled”, to prevent its spread throughout the federal government or to American allies.

It was declassified for release on Wednesday.

The release came against the backdrop of the president presiding over a meeting of world leaders at the United Nations.

“Just so you understand, it’s the single greatest witch hunt in American history, probably in history,” Mr Trump said during a meeting with foreign leaders in New York.

Mr Trump also said “there was no pressure whatsoever” when he spoke with Ukraine’s leader about working with his personal lawyer, Rudy Giuliani, and US attorney general William Barr.

According to the call summary, Mr Trump said: “Mr Giuliani is a highly respected man, he was the mayor of New York City, a great mayor, and I would like him to call you.

“I will ask him to call you along with the attorney general.”

Mr Barr has not discussed anything related to Ukraine with Mr Giuliani, officials said.

The conversation between the two leaders is one piece of a whistleblower’s complaint, which followed the July 25 call.

The complaint is central to the formal impeachment inquiry launched on Tuesday by House Speaker Nancy Pelosi.

The inspector general for the intelligence community wrote to the Director of National Intelligence in August that he believed the conversation between Mr Trump and Ukraine’s leader could have been a federal campaign finance violation because the president could have been soliciting a campaign contribution from a foreign government, a Justice Department official said.

The whistleblower — a member of the intelligence community — said in their complaint that they had heard the information from “White House officials”, but did not have firsthand knowledge of the call, the Justice Department official said.

Prosecutors from the department reviewed a transcript of the call and determined the president did not violate campaign finance law.

Justice Department spokeswoman Kerri Kupec said the attorney general was first notified of Mr Trump’s conversation with the Ukrainian president “several weeks after the call took place”, when the department received the referral about potential criminal conduct.

“The president has not spoken with the attorney general about having Ukraine investigate anything relating to former Vice President Biden or his son. The president has not asked the attorney general to contact Ukraine on this or any other matter,” the spokeswoman said.

Politicians have been demanding details of the whistleblower’s complaint, but the acting director of national intelligence, Joseph Maguire, has refused to share that information, citing presidential privilege.

He is to testify on Thursday before the House, and politicians are expected to have access to details of the complaint beforehand in a classified setting.

The complaint has set off a stunning turn of American political events, leading Ms Pelosi to yield to mounting pressure from fellow Democrats on the impeachment inquiry.

Congress’ probe focuses partly on whether Mr Trump abused his presidential powers and sought help from a foreign government to undermine Mr Biden and help his own re-election.

Ms Pelosi said such actions would mark a “betrayal of his oath of office” and declared, “No one is above the law.”