WASHINGTON — President Trump said on Monday that the White House was “trying to find out” the identity of the whistle-blower whose claims led Democrats to begin an impeachment inquiry last week, even as the whistle-blower’s lawyers have outlined “serious” safety concerns for their client as Mr. Trump has repeatedly targeted him and compared him to a spy.
Mr. Trump’s latest comment, made to reporters in the Oval Office during the swearing-in of his new labor secretary, Eugene Scalia, followed up on a series of Twitter posts over the weekend, in which Mr. Trump claimed that he deserved “to meet my accuser.”
It was not immediately clear what steps the White House was taking to identify the whistle-blower, but the White House has known for weeks that a C.I.A. officer lodged concerns about Mr. Trump’s dealings with Ukraine. Still, Mr. Trump’s fixation on discovering and discussing the identity of the whistle-blower, whose anonymity is protected by law, was seen as a brazen move for a president under scrutiny for abuse of power.
“As the acting D.N.I. testified last week, the law and policy supports protection of the identity of the whistle-blower from disclosure and from retaliation,” Mark Zaid, the lawyer for the whistle-blower, said Monday, referring to the acting director of national intelligence, in response to Mr. Trump’s most recent comments. “No exceptions exist for any individual.”
Mr. Trump on Monday also questioned whether the chairman of the House Intelligence Committee, Representative Adam B. Schiff, should be arrested for treason for his description of a phone call Mr. Trump had with the president of Ukraine during a recent congressional hearing.
A day earlier, Mr. Trump called for Mr. Schiff — the California Democrat who is the de facto head of an impeachment inquiry into the call — to be “questioned at the highest level for Fraud & Treason.”
Mr. Trump has accused Mr. Schiff of lying to Congress when Mr. Schiff summarized a portion of what Mr. Trump said to President Volodymyr Zelensky of Ukraine during a July 25 phone call. Mr. Trump asked Mr. Zelensky to “do us a favor” and investigate Democrats — a request Democrats say is an abuse of power for personal gain. They have started an impeachment inquiry.
Mr. Trump has defended his part of the conversation as “perfect,” and focused on Mr. Schiff’s public retelling of the call, which the president suggested was mischaracterized.
Mr. Trump pointed to Mr. Schiff’s summary of portions of the exchange between the president and Mr. Zelensky and how they veer from the reconstructed transcript of the call released by the White House.
During a House Intelligence Committee hearing on Thursday, Mr. Schiff addressed a portion of the reconstructed transcript and introduced his summary of it saying, “Shorn of its rambling character and in not so many words, this is the essence of what the president communicates.”
Then, Mr. Schiff summarized Mr. Trump’s comments and said: “We’ve been very good to your country, very good. No other country has done as much as we have, but you know what, I don’t see much reciprocity here. I hear what you want. I have a favor I want from you, though.”
The summary appears to be drawn from several portions of the call, including statements from Mr. Trump to Mr. Zelensky.
“The United States has been very very good to Ukraine,” Mr. Trump told Mr. Zelensky. “I wouldn’t say that it’s reciprocal necessarily because things are happening that are not good but the United States has been very very good to Ukraine.”
And later, the president said, “I would like you to do us a favor though because our country has been through a lot and Ukraine knows a lot about it.”
On Sunday, Mr. Trump said of Mr. Schiff in a Twitter post, “His lies were made in perhaps the most blatant and sinister manner ever seen in the great Chamber.” Mr. Trump continued, “He wrote down and read terrible things, then said it was from the mouth of the President of the United States.”
Mr. Schiff on Monday did not immediately respond to a request for comment.
A former prosecutor with experience impeaching federal judges, Mr. Schiff has taken the lead in the impeachment inquiry regarding the president’s phone call with Ukraine. On Sunday he said the anonymous whistle-blower would testify before the House Intelligence Committee “very soon.”
As for Mr. Trump’s accusations of lying to Congress, Mr. Schiff said Sunday on ABC’s “This Week,” “Let’s not pretend that this is really what the president is upset with me about.”
Mr. Schiff said Mr. Trump was “furious with me” because as soon as Mr. Schiff learned a whistle-blower complaint had been filed, he publicly called for its release to Congress.
“The president believes that it is his God-given right to shake down foreign leaders for help in his re-election, and he should not be encumbered by the public finding out about it,” Mr. Schiff said Sunday. “That’s what has incensed the president. And I am willing to take the brunt of that.”
The president’s attack on Mr. Schiff is one of several lines of defense Mr. Trump has embraced since the release of a reconstructed transcript of the phone call and a whistle-blower complaint about the call and the White House’s handling of the call’s records.
In addition to accusing Mr. Schiff of treason, Mr. Trump is calling the impeachment inquiry a “witch hunt,” questioning the source of an anonymous whistle-blower’s information, calling the complaint “fake,” and raising questions about whether the whistle-blower law was changed before the complaint was filed in August.