WASHINGTON — The U.S. House will move forward with an official impeachment inquiry against President Donald Trump over a whistleblower complaint and the president's alleged push to get another country to investigate a political opponent.

"The president must be held accountable. No one is above the law," said House Speaker Nancy Pelosi.

Six different committees will be part of the impeachment inquiry and will report their progress to the house speaker.

More Democrats, including moderates, came forward to endorse the move Tuesday. The announcement came after a Democratic caucus meeting Tuesday afternoon.

Among those Democrats was Rep. Kathy Castor (D-Tampa), who over the summer opposed impeachment proceedings.

"The American people need to understand the facts," Castor told Spectrum News DC reporter Samantha-Jo Roth. "Those committees need to expedite what they are doing so that the facts are made plain all across America."

The new push for impeachment proceedings came after a whistleblower complaint from the intelligence community, which the Trump administration withheld from Congress.

The complaint at least partially stems from questions over whether the president improperly tried to pressure the Ukrainian president to investigate the son of Democratic presidential candidate Joe Biden.

The president himself has admitted bringing up Biden and his son, Hunter, to Ukrainian President Volodymyr Zelenskiy over the summer. The president has tried to tie Hunter Biden, and by extension his father, to political corruption in the country. 

While vice president under President Barack Obama, Biden led diplomatic dealings with the Ukrainian government. At the same time, his son was serving on the board of a Ukrainian gas company.

Trump on Tuesday afternoon tweeted that he had authorized the release of the full "unredacted" transcript of his conversation with Zelenskiy.

Trump also told reporters at the United Nations on Tuesday that he ordered his staff to freeze almost $400 million in aid to Ukraine days before the phone call. He told reporters that he did it to fight corruption and get other European nations to help Ukraine.

The president denies that the request for help in getting damaging information about the Bidens was tied to the freeze.

While the president said he authorized the release of the transcript, there's no word on whether the White House will release the complete whistleblower complaint itself, which was withheld from Congress. 

In the impeachment announcement, Pelosi said the White House had until Thursday to turn it over.

That's also when the acting director of national intelligence Joseph Maguire is set to testify before the House. He refused to turn over the details of the whistleblower complaint, citing presidential privilege.

Pelosi says the move is in violation of the law that created the DNI position in 2004.

The full Senate also unanimously approved a nonbinding resolution Thursday, calling on the Trump administration to immediately provide the House and Senate intelligence committees with copies of the whistleblower complaint.

Pelosi had opposed bringing impeachment proceedings against the president in the past, saying that it wasn't worth it.

Pelosi took part in an interview at an event Tuesday afternoon, and while she did not answer questions on whether she thought the president had conducted any impeachable offenses, she did say his conduct was wrong.

“We don’t ask foreign governments to help us in our election,” Pelosi said.

Democrats Calling for Impeachment Proceedings

It's thought that more than half of Democrats in the House support moving forward with an impeachment inquiry, according to counts by several media outlets. Our Spectrum News DC reporters have been sharing statements from lawmakers over the past couple of days.

Information from the Associated Press and the Spectrum News DC staff contributed to this report.