Trump also repeatedly told the Ukrainian leader, Volodymyr Zelensky, to talk with his personal lawyer Rudolph W. Giuliani, who had been urging the government in Kiev to investigate Biden and his family, according to two other people briefed on the call.
Trump’s request is part of the secret whistle-blower complaint that is said to be about Trump and at least in part about his dealings with Ukraine, according to two people familiar with the complaint.
Biden is a leading candidate for the Democratic presidential nomination. The president has made no secret that he wanted Ukraine to investigate any improper overlap between Biden’s own diplomatic efforts there and his son’s role with a gas company owned by a Ukrainian oligarch. “Someone ought to look into Joe Biden,” Mr. Trump told reporters on Friday in response to a question about his call with Zelensky.
The revelations added urgency to questions about Trump’s dealings with Ukraine, which is battling Russian-controlled separatists in the country’s east. When the president sought the Biden investigation, the Trump administration’s military aid to Ukraine had been frozen for weeks.
The United States suspended that assistance in early July, according to a former American official. Trump did not discuss the aid in the July 25 call with Mr. Zelensky, whose government did not learn of the suspension until August, according to people familiar with the call. The Wall Street Journal first reported details of the call.
For Democrats who want to examine the whistle-blower complaint — itself the subject of an internal administration dispute over whether to hand it over to Congress, as is generally required by law — the key question is whether Trump was demanding a quid pro quo, explicitly or implicitly. Democratic House committee chairmen are already investigating whether he manipulated American foreign policy for personal political advantage and have requested the transcript of the Zelensky call.
The growing controversy had echoes of the dominant scandal of the first years of Mr. Trump’s administration: whether his campaign sought help from Russia to benefit him in 2016. Ultimately, the special counsel found that although “insufficient evidence” existed to determine that Mr. Trump or his advisers engaged in a criminal conspiracy with the Russians, his campaign welcomed Moscow’s election sabotage and expected to benefit from it.
Any attempt by Trump to ask a foreign power to “dig up dirt” on a political rival while withholding aid is corrupt, said Representative Adam B. Schiff, Democrat of California and the chairman of the House Intelligence Committee, one of the panels examining Trump’s Ukraine dealings.
“No explicit quid pro quo is necessary to betray your country,” tweeted Schiff, who has also pushed for the whistle-blower complaint to be given to Congress.
Any effort by Trump to pressure a foreign government to dig up dirt on his political opponent, while holding up vital military aid to that country, is both corrupt and a grave threat to American interests.
No explicit quid pro quo is necessary to betray your country. https://t.co/SoJFFOLV1g
— Adam Schiff (@RepAdamSchiff) September 20, 2019
Trump opened a direct counterattack on Friday against the whistle-blower, whose identity is unknown, as are many details about the complaint. The president dismissed the allegations and labeled the whistle-blower, without evidence, a political partisan.
“It’s a ridiculous story. It’s a partisan whistle-blower,” Trump told reporters in the Oval Office, though he acknowledged he did not know the person’s identity. “They shouldn’t even have information.”
Trump and Giuliani have pressed for an investigation of the Bidens for weeks, after reports this year in The New York Times and elsewhere examined whether a Ukrainian energy company sought to buy influence in Washington by hiring Biden’s younger son, Hunter Biden. The younger Biden had a lobbying business in Ukraine while his father was vice president.
On Friday, the former vice president accused Trump in a statement of using the power of the United States to extract “a political favor.” Biden called for the president to release the transcript of his call with Zelensky and said that if the reports about it proved true, “there was no bottom to President Trump’s willingness to abuse his power and abase our country.”
He also said the allegations that he or his son committed wrongdoing in Ukraine were baseless. “Not one single outlet has given any credibility to his assertion,” Biden told reporters after a campaign event in Cedar Rapids, Iowa.
Controversy over the Trump administration’s Ukraine policy has swirled for weeks but has been confined mostly to foreign policy experts. The revelations about the whistle-blower complaint plunged the issue into the center of the political debate.
Congress has still not seen the whistle-blower’s allegation. Although the inspector general for the intelligence community, Michael Atkinson, has sought to provide it, the acting director of national intelligence, Joseph Maguire, has blocked him in a dispute over legal requirements.
Maguire and his general counsel decided against providing the complaint to Congress after consulting with Pat A. Cipollone, the White House counsel, according to a person familiar with the move.
Mounting evidence that the White House was involved in the effort to withhold the complaint from lawmakers has stirred anger on Capitol Hill. Speaker Nancy Pelosi accused Maguire of violating the law.
“If the president has done what has been alleged, then he is stepping into a dangerous minefield with serious repercussions for his administration and our democracy,” she added in a statement.
Republicans were largely silent about Trump’s calls for a foreign investigation of his political rival. Their apparent desire to avoid criticizing the president during a political crisis stood in contrast to the criticism from party members after the administration froze aid to Ukraine.
The administration, critics said, has struggled to explain the move, which has convinced some Democrats that it was part of an effort bring about a Biden investigation.
“They have no shame,” said Michael Carpenter, a former aide to Biden and expert on Ukraine. He added: “They released the assistance in mid-September after the bipartisan uproar over the freeze — and under pressure from the House investigations. But strikingly, the administration never articulated why the assistance was frozen in the first place.”
Giuliani has spearheaded a push for a Biden inquiry. He met with Zelensky’s emissaries this summer in hopes of encouraging his government to pursue investigations into the family as well as whether Ukrainian officials took steps during the 2016 election to damage Trump’s campaign.
Giuliani has said he was acting on his own, though his comments on Thursday seemed to draw a closer connection to Mr. Trump. “A President telling a Pres-elect of a well known corrupt country he better investigate corruption that affects US is doing his job,” Giuliani tweeted shortly after an appearance on CNN, where he first denied, then admitted, asking the government in Kiev to investigate the Bidens.
Although they agreed to meet with Giuliani, the Ukranians have so far refused to open the investigations. But there is little doubt the pressure from Trump is causing stress on the new government, according to a former Ukrainian official.
Since 2014, Ukraine has been under attack by Russia and its proxy, a fight that has become a grinding conflict that has made it difficult for Kiev to continue its overhaul efforts and work to become more integrated with Europe and the West.
But now Ukraine also finds itself potentially at odds with the leader of its most critical partner, the United States, and at the center of a political battle in Washington.
They will meet each other next week on the sidelines of the United Nations General Assembly in New York, a senior administration official confirmed on Friday after Zelensky’s office announced the meeting. But the administration has put off any commitment for a White House meeting, which Zelensky views as critical for the relationship.