"The complaint states that the White House tried to lock down all records of the call, especially the word-for-word transcript," Pelosi, D-Calif., told reporters Thursday morning at a news conference in the Capitol. "That gave the whistleblower reason to believe that they - the White House - understood the gravity of what transpired in that call."
In the whistleblower’s letter to Sen. Richard Burr and Rep. Adam Schiff, the respective chairs of the Senate and House Intelligence committees, the complaint outlines several conversations the whistleblower had with “multiple White House officials.”
“According to multiple White House officials I spoke with, the transcript of the President's call with President Zelenskyy was placed into a computer system managed directly by the National Security Council (NSC) Directorate for Intelligence Programs,” the whistleblower noted in a letter to Sen. Richard Burr and Rep. Adam Schiff, the respective chairs of the Senate and House Intelligence committees. “This is a standalone computer system reserved for codeword-level intelligence information, such as covert action. According to information I received from White House officials, some officials voiced concerns internally that this would be an abuse of the system and was not consistent with the responsibilities of the Directorate for Intelligence Programs.”
The White House did not immediately respond to ABC News' request for comment on Pelosi's claims.
Pelosi told reporters she believes the acting Director of National Intelligence Joseph Maguire broke the law by not turning over the whistleblower complaint to the intelligence committees immediately after learning of the matter.
"I think what the DNI did was broke the law," Pelosi said. "The law is very clear: the DNI shall convey the complaint to the intelligence committees – not the whole Congress – to the intelligence committee. Carefully balanced to protect our intelligence and to protect the whistleblower."
Pelosi said Maguire’s efforts to seek the White House’s assistance to determine whether it was appropriate to share the document with Congress was "wrong."
At a House Intelligence Committee hearing on Thursday, Maguire defended his handling of the complaint and said the White House “did not direct me to withhold the information.”
“The question came down to ‘urgent concern,’ which is a legal definition,” Maguire testified. “It doesn't mean, is it important, is it timely?”
“Just because it was not forwarded to this committee does not mean that it went unanswered,” he added. “The [Intelligence Community Inspector General] and the Justice Department referred it to the Federal Bureau of Investigation for investigation. And that was working while I was endeavoring to get the executive privilege concerns addressed.”
Maguire insisted he was not “stonewalling.”
“I didn't receive direction from anybody. I was trying to work through the process and the law the way it is written,” he said. “I have to comply with the way the law is, not with the way some people would like it to be. If I could do otherwise, it would have been more convenient for me.”
Maguire also defended his handling of the complaint and said the White House did not ask him to hide anything.
"The White House did not direct me to withhold the information. Neither did the office of legal counsel. That opinion is unclassified and has been disseminated. The question came down to urgent concern, which is a legal definition. It doesn't mean is it important, is it time urgent concern met the criteria we discussed several times here," Maguire said.
"All that did was just take away the seven days. As I said before, just because it was not forwarded to this committee does not mean that it went unanswered. The IC IG and the Justice Department referred it to the Federal [Bureau] of Investigation for investigation. And that was working while I was endeavoring to get the executive concerns addressed," Maguire continued.
"It was not stonewalling. I didn't receive direction from anybody. I was trying to work through the process and the law the way it is written. I have to comply with the way the law is, not with the way some people would like it to be. If I could have done otherwise, it would have been more convenient for me," Maguire said.
After announcing Tuesday that the House of Representatives was proceeding with "an official impeachment inquiry," Pelosi deferred questions about the timing of the impeachment inquiry to her colleagues leading the investigation.
"When the committee finishes its work and we have the work that has already been done by the chairs, there will be some determination about how we proceed, but I’m not going to go into that today," Pelosi demurred.
"The inquiry and the consensus in our caucus is that our focus now is on this allegation -- now we are seeing the evidence of it -- and why the president thinks that this is exculpatory," Pelosi said. "Maybe he doesn’t know that word; the president thinks this proves his innocence only goes to show he doesn’t know right from wrong."
Pelosi said it’s been "a sad week for our country" after Democrats "very prayerfully and patriotically" reached the decision to move forward with an impeachment inquiry.
"This is nothing that we take lightly and in trying to balance our responsibility to protect and defend the constitution of the United States, in a way that was not divisive in our country, but uniting in our country we wanted to have a fuller understanding of the facts," Pelosi said. "Last week we saw something that removed all doubt as to whether we should move forward with this distinct change in the body of knowledge that we had to make this decision."
While Pelosi has worked for months to proceed methodically through congressional investigation into the Trump administration, she denied that her announcement signaled a shift in strategy , she denied that her announcement signaled a shift in strategy.
"When people say to me, 'What made you change my mind?' I didn’t change my mind. I’ve always been on the course of finding the facts as we honor our constitution," Pelosi said. "And the facts are these: that the president of the United States and his actions in a telephone call with a head of state betrayed his oath of office, our national security and the integrity of our elections. This is about the facts, this about the constitution of the United States and we have to make a judgment in an inquiry as we go forward."
Pelosi also dismissed members of her caucus who are eager to press forward with a floor vote on articles of impeachment.
"No, we have to have an inquiry to further establish the facts," she stressed. "There is no rush to judgment and in some ways we are a jury open to what might be exculpatory or not. But every day, the sadness grows because the disregard for our constitution that the president has becomes more clear."
Later Thursday, Pelosi called the move toward impeachment a “sad step” during a pro-choice event in D.C.
“I never thought we would see a president take the actions that he has -- in fact, I don’t think our founders ever thought a president would do such a thing,” Pelosi said.
Pelosi denied the move toward impeachment was political, instead saying that she is protecting the Constitution.
“I know this is not a political occasion, and I don’t think the action of an inquiry is political move," she said. "It’s not about politics, it’s not about partisanship, it’s about patriotism … It’s about protecting our Constitution.”
While her comments were met with applause, she told the crowd impeachment should not be cause for celebration.
“This is not a celebration to say we’ve taken this step," she said. "It’s a really sad step for us to have to take. But sadly, we had no choice.”
ABC News' Liz Alesse contributed to this report