U.S. President Donald Trump told reporters on April 4 that the inspector-general of the intelligence community he fired the previous day had taken "a fake report and took it to Congress with an emergency," lending weight to accusations that the dismissal was retaliation connected to Trump's congressional impeachment over pressure he put on Ukraine.

Trump informed the Senate Intelligence Committee late on April 3 that he had fired Michael Atkinson, the intelligence official who handled the 2019 whistle-blower complaint that described the president’s pressure in a July 2019 phone call with Ukraine's president to investigate Trump political rival Joe Biden and his son.

"I thought he did a terrible job, absolutely terrible." Trump told reporters on April 4. "He took a fake report and he took it to Congress with an emergency, OK? Not a big Trump fan, that I can tell you."

The whistle-blower complaint, written by an anonymous intelligence official, described accounts of the phone call with Ukrainian President Volodymyr Zelenskiy in which Trump asked for "a favor" and urged investigation of Biden and his son.

Atkinson reportedly determined the complaint was urgent and credible and therefore was required to be disclosed to Congress. But Atkinson was overruled for several weeks by the acting director of national intelligence before public reports of the complaint prompted its publication with redactions.

An inquiry in Congress led to the Democratically controlled House of Representatives passing two articles of impeachment against Trump in December. The Republican-controlled upper house, which tries impeachment cases, acquitted Trump in February.

“Never came in to see me, never requested to see me,” Trump said of Atkinson in his remarks on April 4, adding: "That man is a disgrace to IGs [inspectors-general]."

He repeated his earlier description of the phone call with Zelenskiy as "perfect" and said it had been wrongly described in the whistle-blower's account.

The partial transcript released by the White House appeared to largely corroborate the whistle-blower's account, although Zelenskiy later said that he had never felt "pressured" by Trump.

Michael Horowitz, chairman of an independent federal watchdog within the executive branch called the Council of the Inspectors General on Integrity and Efficiency (CIGIE), vowed after Atkinson's firing that the U.S. inspector-general community "will continue to conduct aggressive, independent oversight of the agencies" it oversees.

Horowitz, who also has been the inspector-general of the U.S. Department of Justice since 2012, said on April 4 that Atkinson was known for his "integrity, professionalism, and commitment to the rule of law and independent oversight."

Horowitz said the committee would work "on behalf of U.S. taxpayers, families, businesses, patients, and health-care providers to ensure that more than $2 trillion in emergency federal spending is being used consistently with the law's mandate."

Democrats have expressed concerns about how the recently approved fiscal package to combat the social and economic devastation of the current COVID-19 pandemic will be disbursed by the U.S. Treasury, whose secretary answers to the president.

Atkinson's firing elicited questions from Democrats but also from some prominent Republicans.

Senator Chuck Grassley (Iowa-Republican), who heads the Finance Committee in the upper house, said Congress was "crystal clear" that written reasons were required when inspectors-general are removed for cause.

“More details are needed from the administration," Grassley said.

Another Republican, Senator Susan Collins (Maine), who is on the Senate Intelligence Committee, suggested Trump's rationale for firing Atkinson outlined in his April 3 letter might be insufficient. The dismissal, she said, "was not warranted."

Another Republican, Senate Intelligence Committee Chairman Richard Burr (North Carolina), said an inspector-general "must be allowed to conduct his or her work independent of internal or external pressure.”

Trump's letter was addressed to Representative Adam Schiff (Democrat-California), the head of the House Intelligence Committee, and Devin Nunes (Republican-California), the top Republican on the committee.

Schiff called the firing a "blatant attempt to gut the independence of the Intelligence Community and retaliate against those who dare to expose presidential wrongdoing."

"It puts our country and national security at even greater risk," Schiff tweeted.

Trump wrote that he plans to nominate an individual “who has my full confidence” to replace Atkinson at a later date.

The senior Democrat on the Senate intelligence panel, Senator Mark Warner (Virginia), said that "we should all be deeply disturbed by ongoing attempts to politicize the nation’s intelligence agencies."

With reporting by AP, Reuters, and dpa