WASHINGTON (NYTIMES/AP) - United States President Donald Trump used the power of his office to try to get Ukraine to interfere in the 2020 election to investigate a political rival, according to an explosive whistle-blower complaint released on Thursday (Sept 26) after days of damning revelations about Mr Trump's dealings with Ukraine.

Attorney-General William Barr and the President's personal attorney Rudy Giuliani were central to the effort, the complaint said.

Members of the House and Senate intelligence committees and a group of senior lawmakers from both parties, including Senator Mitch McConnell, the majority leader, were permitted to review the classified complaint on Wednesday, just hours after the White House released a reconstructed transcript of a July 25 call between Mr Trump and President Volodymyr Zelensky of Ukraine.

During the call, about the country's need for more American financial aid, Mr Trump urged Mr Zelensky to pursue an investigation into a political rival, former vice-president Joe Biden.

The unclassified version was released ahead of a House Intelligence Committee hearing where the acting director of National Intelligence, Mr Joseph Maguire, was scheduled to testify.

Mr Maguire told the House Intelligence Committee in public testimony on Thursday that he believes the whistle-blower and the intelligence community's inspector-general acted in "good faith".

Mr Maguire says he upheld his "responsibility to follow the law every step of the way" as he reviewed an intelligence community whistle-blower's complaint detailing President Trump's interactions with the President of Ukraine.

House Democrats have criticised Mr Maguire for withholding the complaint for weeks. The complaint was released to Congress on Wednesday and to the public on Thursday just before the hearing.

Mr Maguire says he could not legally release the complaint because of executive privilege, which he says is a privilege he "did not have the authority to waive". He says he believes the matter is "unprecedented".

The complaint shows Mr Trump urged Mr Zelensky to investigate Mr Biden in a July phone call. Mr Trump has denied doing anything wrong.

The Office of the Director of National Intelligence provided lawmakers with an unclassified version of the whistle-blower complaint so that it could be discussed in the open hearing.

Though the reconstructed transcript of the call has been released, the complaint, filed in August by an intelligence official, contains more details than the phone call, including the names of White House officials who may have witnessed presidential misconduct and other actions.

House Democrats have said that Mr Trump violated his oath of office when he pressured a foreign leader to investigate one of his political rivals.

The White House initially refused to provide Congress with the complaint or to reveal what was said on the call. After Democrats took the first steps to impeach Mr Trump, the administration disclosed details of the call and shared the classified complaint with lawmakers.

The allegations it contained were "deeply disturbing" and "very credible", Representative Adam B. Schiff, the chairman of the Intelligence Committee, said on Wednesday after reviewing the complaint.

Mr Trump has dismissed the allegations that he acted improperly.

Early on Thursday morning, the President was busy sharing on Twitter praise from some of his allies and issued his own view: Most Republican lawmakers and allies of the President did not break with Mr Trump after the contents of the July 25 phone conversation were made public.

"If you are underwhelmed by this transcript, you are not alone or 'crazy'," Senator Lindsey Graham said in a Twitter post on Wednesday.

Mr Graham served as a House prosecutor during the impeachment trial of former president Bill Clinton in 1999.

"Those willing to impeach the president over this transcript have shown their hatred for @realDonaldTrump overrides reason."

Mr Graham is not a member of the Senate Intelligence Committee and would not have been among the lawmakers permitted to see the full classified complaint on Wednesday.