President Donald Trump said Tuesday he had authorized the release of the "complete, fully declassified and unredacted" transcript of a July phone call he had with Ukrainian President Volodymyr Zelensky that is at the center of questions stemming from reports that Trump pressured him to investigate the family of former Vice President Joe Biden.

Trump has been under fire for the midsummer call after a whistleblower complaint alleged that the president may have made inappropriate comments on the call. The call prompted questions about whether Trump may have tied aid to Ukraine to the country’s willingness to investigate business dealings of Biden’s son.

"You will see it was a very friendly and totally appropriate call. No pressure and, unlike Joe Biden and his son, NO quid pro quo! This is nothing more than a continuation of the Greatest and most Destructive Witch Hunt of all time!" Trump tweeted.

....You will see it was a very friendly and totally appropriate call. No pressure and, unlike Joe Biden and his son, NO quid pro quo! This is nothing more than a continuation of the Greatest and most Destructive Witch Hunt of all time! — Donald J. Trump (@realDonaldTrump) September 24, 2019

The release of the transcript by the White House isn't likely to appease Democrats, who have demanded that the administration provide the whistleblower complaint to Congress and who in increasing numbers are coming out in support of some form of impeachment action against Trump. House Speaker Nancy Pelosi announced a formal impeachment inquiry later on Tuesday, saying that "no one is above the law."

The White House is preparing to turn over the whistleblower complaint by this Thursday, according to a senior administration official.

That official tells NBC News the complaint will undergo a classification review and be provided to Congress by Thursday.

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Acting Director of National Intelligence Joseph Maguire is scheduled to testify before the House Intelligence Committee on Thursday. Maguire and the national intelligence inspector general, Michael Atkinson, are also set to appear before the Senate Intelligence Committee behind closed doors Thursday afternoon.

Lawyers for the whistleblower approached Maguire for "guidance" on arranging a potential meeting with members of the House and Senate intelligence committees. The Senate on Tuesday voted unanimously on a nonbinding resolution calling on Trump to release the whistleblower complaint.

Earlier Tuesday, Trump had confirmed reports that his administration froze almost $400 million in aid to Ukraine. But he gave a new reason for doing so: He said he wanted European countries to contribute money, too, and did not want the United States to do so alone.

"As far as withholding funds, those funds were paid," Trump said. "They were fully paid. But my complaint has always been — and I'd withhold again, and I'll continue to withhold until such time as Europe and other nations contribute to Ukraine, because they're not doing it."

"Very important, I want other countries to put up money," he added. "I think it's unfair that we put up the money. Then other people call me. They said, 'Oh, let it go.' And I let it go. But we paid the money, the money was paid."

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He said he wants Germany, France and other nations to contribute more funds.

"And that's been my complaint from the beginning," he said.

Trump's Tuesday explanation was a sharp turn from remarks he made on Monday tying the freezing of funds to Ukraine's efforts to combat corruption.

"We want to make sure that country is honest," Trump told reporters on Monday. "It's very important to talk about corruption. If you don't talk about corruption, why would you give money to a country that you think is corrupt?"

Trump's latest remarks come amid revelations surrounding the president's apparent push to have the Ukrainian government investigate Biden's son, Hunter, who had business dealings in the country.

The late July discussion between Trump and Zelensky has been scrutinized following a whistleblower complaint by a member of the U.S. intelligence community that media reports said was tied to the call between the two leaders. The administration had refused to turn that complaint over to Congress.

On Monday, The Washington Post and other media outlets reported that Trump instructed his acting chief of staff to place a hold on about $400 million in military aid for Ukraine in the days before the late July phone call with Zelensky. The White House labeled the reporting as untrue.

But in the weeks before the existence of the whistleblower complaint became public knowledge, the Trump administration froze the military aid to Ukraine for unclear reasons. Then, just before Democrats revealed the existence of the whistleblower complaint, the administration released the hold on the aid.

The administration put a hold on the money during the week of July 18, one week prior to Trump's phone call with Zelensky, two administration officials told NBC News Tuesday. The administration official who directed the State Department to withhold the Ukrainian aid was acting chief of staff Mick Mulvaney, according to a senior Democratic aide briefed last week by the State Department.

The episode has led to an increased impeachment push among House Democrats. By Tuesday afternoon, over 180 House Democrats — over three-quarters of the 235-member caucus — said they now back some type of impeachment action in light of the burgeoning Ukraine scandal. More than a dozen lawmakers have announced such support since the reports emerged about the president's conversation with Zelensky.

Speaking to reporters ahead of his speech to the U.N. on Tuesday, Trump called the ratcheting up of impeachment talk "ridiculous" and a "witch hunt," before insisting that his call with Zelensky "was perfect."

Trump has admitted to talking about Biden, his political rival, with Zelensky, but denied putting any pressure on the Ukrainian leader.