WASHINGTON, Sept. 26 (Xinhua) -- Partisan fight in the United States has intensified after a congressional panel on Thursday released a declassified version of a whistleblower complaint on President Donald Trump's interactions with his Ukrainian counterpart Volodymyr Zelensky.

In the whistleblower complaint, which was filed on Aug. 12 by an unidentified intelligence official and released by the Democrat-controlled House Intelligence Committee, the official warned that Trump was "using the power of his office to solicit interference from a foreign country in the 2020 U.S. election."

The official said that the interference included "pressuring a foreign country to investigate one of the President's main domestic political rivals," adding that Trump's personal lawyer, Rudy Giuliani, was "a central figure in this effort."

The whistleblower cited White House officials who had direct knowledge of the July 25 phone call between Trump and Zelensky as saying Trump pressured Zelensky to "initiate or continue an investigation into the activities of Former Vice President Joseph Biden and his son, Hunter Biden."

The whistleblower used the full version of Biden senior's first name, which, however, is more often referred to as Joe. Biden is a Democratic presidential candidate running for the 2020 election.

The whistleblower's accounts seemed to have been proven in the rough transcript of the call released Wednesday by the White House. Trump mentioned Biden several times during the call, at one time suggesting that the Ukrainian president cooperate with Giuliani and U.S. Attorney General William Barr in investigating into how the former vice president stopped a prosecution of a Ukrainian gas company which might be related to his son.

"I heard you had a prosecutor who was very good and he was shut down and that's really unfair," Trump told Zelensky, the transcript showed. Referring to Giuliani, Trump said, "I will ask him to call you along with the Attorney General ... If you could speak to him that would be great."

"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 attorney general would be great," Trump said.

Zelensky told reporters Wednesday at a much-anticipated bilateral meeting with Trump in New York that nobody had pushed him. He said he didn't want to be involved in the U.S. election, and that the phone call with Trump was "good" and "normal."

According to the whistleblower, White House officials said they were "disturbed by what had transpired" in the Trump-Zelensky conversation, telling the whistleblower that they were already in discussion with White House lawyers about "how to treat the call because of the likelihood, in the officials' retelling, that they had witnessed the president abuse his office for personal gain."

But then, the whistleblower learned from multiple U.S. officials in the days following the phone call that senior White House officials had engaged in blocking "all records of the phone call."

Senior White House officials, the whistleblower said, "had intervened to 'lock down' all records of the phone call, especially the official word-for-word transcript of the call that was produced -- as is customary -- by the White House Situation Room. This set of actions underscored to me that White House officials understood the gravity of what had transpired in the call."

According to the whistleblower complaint, Giuliani acted as a conduit between Trump and Ukrainian officials, relaying messages back and forth. His role, the whistleblower said, had raised concerns among U.S. officials, who had spoken with Giuliani "in an attempt to 'contain the damage' to U.S. national security."

Giuliani disputed the whistleblower's accounts. He was cited by the CNN as saying Thursday morning that, claims that U.S. officials were "deeply concerned" about his interactions with Ukrainian officials were "total nonsense."

"At no time did either one of them say they wanted to contain damage," Giuliani said. "At no time did the State Department in communication with me ever relay any of that information you're talking about."

The whistleblower further noted that during the time period starting in mid-May, Kurt Volker, U.S. special representative for Ukraine negotiations, and Gordon Sondland, U.S. ambassador to the European Union, once met with members of the new administration in Kiev and "sought to help Ukrainian leaders understand and respond to the differing messages they were receiving from official channels on the one hand, and from Mr. Giuliani on the other."

The whistleblower also expressed confusion over Trump's mentioning in the phone call of U.S. cyber security firm CrowdStrike, which the Democratic National Convention (DNC) hired in 2016 to investigate hacks into its computers.

The whistleblower, also citing White House officials, said Trump asked Zelensky to "locate and turn over" the servers used by the DNC and examined by CrowdStrike. This request from Trump to Zelensky, according to the whistleblower, was meant to let the Ukrainian leader "assist in purportedly uncovering that allegations of Russian interference in the 2016 U.S. presidential election originated in Ukraine."

Trump suggested that Zelensky coordinate with Giuliani and Barr in this effort, according to the whistleblower.

"I do not know why the President associates these servers with Ukraine," the whistleblower wrote in a footnote in the complaint.

Trump in the phone call asked Zelensky to do the United States "a favor" by "getting to the bottom" of the matter, according to the transcript of the call.

"I would like you to find out what happened with this whole situation with Ukraine, they say CrowdStrike," said the president, "The server, they say Ukraine has it."

Acting Director of National Intelligence Joseph Maguire, who was under pressure from Congress to hand in the whistleblower complaint, told the House Intelligence Committee during his testimony Thursday that he believed the whistleblower and Inspector General of the Intelligence Community Michael Atkinson "have acted in good faith throughout."

Describing the issue as "of urgent concern," Maguire told lawmakers, "I want to say once again, I believe that the situation we have and why we're here this morning is because this case is unique and unprecedented."

In the wake of the release of the complaint, House Speaker Nancy Pelosi, who on Tuesday announced a formal impeachment inquiry into Trump, reiterated the necessity of the inquiry, while cautioning "no rush to judgment."

"There are some in our caucus who think let's just have an impeachment. No, we have to have an inquiry to further establish the facts," the Democratic congresswoman said at her weekly news conference.

"But every day, the sadness grows because the disregard for our Constitution that the President has becomes more clear," she added.