WASHINGTON—President Trump sought to use the powers of his office to push Ukraine to investigate Democratic rival Joe Biden, and White House officials acted to conceal evidence of the president’s actions, a whistleblower complaint alleges.
The whistleblower’s complaint, released Thursday, concerns a July phone call between Mr. Trump and President Volodymyr Zelensky of Ukraine. The controversy has become the biggest political danger to Mr. Trump’s presidency as it rallied House Democrats this week to launch impeachment proceedings.
“In the course of my official duties, I have received information from multiple U.S. government officials that the President of the United States is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election,” the complainant wrote. “This interference includes, among other things, pressuring a foreign country to investigate one of the President’s main domestic political rivals.”
The whistleblower complaint emphasized that Mr. Trump sought to cajole Mr. Zelensky into working with his personal lawyer Rudy Giuliani—who was described as a “central figure in this effort”—and Attorney General William Barr in such an investigation, as a memorandum of the call released Wednesday by the White House also showed.
The complaint paints a picture of several White House officials racked with concern about the president’s activities, describing them as “deeply disturbed” about the call.
“There was already a ‘discussion ongoing’ with White House lawyers about how to treat the call because of the likelihood, in the officials’ retelling, that they had witnessed the president abuse his office for personal gain,” the complaint said.
The complaint alleges that there was an effort within the White House in the days after the call to “lock down” all records related to it, “especially the word-for-word transcript of the call that was produced” by the White House Situation Room.
The whistleblower, whose identity hasn’t been made public, works for the Central Intelligence Agency, according to a person familiar with the matter.
The House Intelligence Committee released the complaint Thursday morning shortly before the acting director of national intelligence, Joseph Maguire, testified about it before the panel.
White House officials said Thursday that they still were grappling with the implications of the complaint. One administration official said White House and national security officials were trying to steer clear of conversations involving Ukraine to avoid getting ensnared in the fallout.
Some allies of the Republican president fretted privately that the complaint and the coming House impeachment proceedings could damage Mr. Trump’s re-election prospects, even as the president and his advisers publicly argued that Democrats were overreaching and would face a backlash from voters.
White House officials said they remained confident that most Republicans in the Senate—where the Constitution requires a two-thirds majority to convict if the House votes to impeach—would continue standing behind the president.
White House press secretary Stephanie Grisham said: “Nothing has changed with the release of this complaint.” The president “has nothing to hide,” she said. Mr. Giuliani in an interview Thursday called the complaint ridiculous.
In comments at Joint Base Andrews, Mr. Trump blasted the Democrats. “What these guys are doing, Democrats, are doing to this country is a disgrace,” he said.
During a visit earlier Thursday to the staff of the U.S. mission to the United Nations in New York, Mr. Trump criticized those who leak to the media or whistleblowers, suggesting they are spies who must be dealt with and that the conduct was treasonous, according to two people familiar with his remarks. The people said it was clear the president wasn’t joking.
The complaint was released along with a letter from the intelligence community’s inspector general that deemed the complaint urgent and credible.
The complaint, submitted in August, focused on the July 25 call between Mr. Trump and Ukraine’s president. It said it also drew from testimonials of more than a half-dozen unidentified U.S. officials who expressed concern about Mr. Trump’s conduct.
On the call, Mr. Trump pressed Mr. Zelensky to investigate Joe Biden and his son, Hunter, according to the memorandum released by the White House. During the call, Mr. Trump mentioned the aid that the U.S. provides Ukraine, but didn’t present it as an explicit quid pro quo for a probe of the Bidens.
On the call, Mr. Trump raised a discredited claim: that as vice president, Mr. Biden called for the ouster of Ukraine’s prosecutor general to protect his son, who sat on the board of a Ukrainian company whose owner the prosecutor had investigated.
The prosecutor was the target of widespread criticism from the U.S. and other countries and had in fact hampered the investigation into the company, Burisma Group. Ukraine’s prosecutor general in May said he had no evidence of wrongdoing by Mr. Biden or his son.
White House officials told the complainant that they had been “directed” by White House lawyers to remove the electronic transcript from the computer system that stores such transcripts and allows for distribution to cabinet-level officials, and instead store it on a separate system reserved for handling highly classified information, the report said.
“This set of actions underscored to me that White House officials understood the gravity of what had transpired in the call,” the complaint said, noting also that White House officials said this wasn’t the first time the Trump White House had put a presidential transcript in the tightly controlled system.
A former White House official familiar with National Security Council computer systems said it would be “highly unusual” for material regarding Mr. Trump’s call with the Ukrainian leader to be put on the tightly restricted computer system reserved for the most secret material, such as information about U.S. covert actions and counterintelligence issues.
The declassified complaint, which contains some redactions, also states that the whistleblower learned from U.S. officials that Mr. Trump instructed Vice President Mike Pence to cancel a planned trip to Ukraine to attend Mr. Zelensky’s inauguration. Energy Secretary Rick Perry led a delegation instead, and the officials said that it was “made clear” to them that Mr. Trump didn’t want to meet with Mr. Zelensky until Mr. Trump saw how his counterpart “chose to act.”
Mr. Trump’s comments during a news conference on Wednesday suggesting that lawmakers should ask for transcripts of Mr. Pence’s calls with Mr. Zelensky weren’t off-handed, according to a senior administration official. Some in the administration have discussed releasing the transcripts of Mr. Pence’s calls after a review of them didn’t raise any red flags, a senior administration official said, adding that the idea has caught the president’s attention. Mr. Pence has had two known telephone calls and one in-person meeting with Mr. Zelensky.
In a separate Aug. 26 letter released by the House Intelligence Committee, Intelligence Community Inspector General Michael Atkinson said he had sent a notice to the White House requesting access to and the “preservation of any and all records” related to Mr. Trump’s July 25 phone call with the Ukrainian leader.
Mr. Atkinson, who was appointed by Mr. Trump, argued that the president’s alleged use of his office to solicit foreign help in a U.S. election—which is against the law—falls under the Office of the Director of National Intelligence’s purview because that office is charged with helping safeguard U.S. elections from foreign interference.
Democrats said the transcript and the complaint further bolstered the need for their impeachment inquiry.
Many Republicans have defended Mr. Trump’s activities as routine communications with a foreign leader, and characterized the Democrats’ interest in the matter as a witch hunt designed to drive the president out of office.
Mr. Maguire had earlier referred the whistleblower report to the Justice Department for a possible investigation into whether Mr. Trump had committed campaign-finance violations, department officials said on Wednesday. Justice Department officials concluded within weeks that there wasn’t enough evidence to open a criminal probe and declined to do so.
In his testimony Thursday, Mr. Maguire defended his handling of the complaint.
“The situation we have and why we’re here this morning is because this case is unique and unprecedented,” he told the committee, while declining to say whether he had discussed the whistleblower complaint with the president.
Republicans played off of that, claiming that Democrats were impugning the integrity of a man who has spent decades in public service. Democrats said they weren’t questioning Mr. Maguire’s honor, but instead his judgment.
At the start of the hearing, House Intelligence Committee Chairman Adam Schiff (D., Calif.) likened Mr. Trump’s request that his Ukrainian counterpart “do us a favor” to the behavior of a mob boss. He cast Mr. Trump’s stance as effectively asking: “I want you to make up dirt on my political opponent. Understand, lots of it?”
Republicans criticized Mr. Schiff, claiming that he was manufacturing a narrative. “I had someone just text me, ‘Is he making this up?’” said Rep. Mike Turner (R., Ohio). “Yes, he was.”
It is possible the whistleblower could appear privately before the intelligence committees as soon as later this week. But the whistleblower and his legal team have taken increased security measures amid concerns for their personal safety, according to people familiar with the matter. There are also concerns that speaking directly to Congress would lead to a leak of the whistleblower’s identity, these people said.
“Publishing details about the whistleblower will only lead to identification of someone, whether our client or the wrong person, as the whistleblower,” Mark Zaid, an attorney representing the whistleblower, said in a statement. “This will place this individual in a much more dangerous situation, not only in their professional world but also their possible personal safety.”
Write to Dustin Volz at dustin.volz@wsj.com, Warren P. Strobel at Warren.Strobel@wsj.com and Siobhan Hughes at siobhan.hughes@wsj.com