WASHINGTON — The Trump administration directed a top American diplomat involved in its pressure campaign on Ukraine not to appear Tuesday morning for a scheduled interview in the House’s impeachment inquiry.
The decision to block Gordon D. Sondland, the United States ambassador to the European Union, from speaking with investigators for three House committees is certain to provoke an immediate conflict with potentially profound consequences for the White House and President Trump. House Democrats have repeatedly warned that if the administration tries to interfere with their investigation, it will be construed as obstruction, a charge they see as potentially worthy of impeachment.
Democrats from the House Intelligence, Foreign Affairs and Oversight committees did not immediately respond on Tuesday.
But in making the decision, hours before he was scheduled to sit for a deposition in the basement of the Capitol, the Trump administration appears to be calculating that it is better off risking the House’s ire than letting Mr. Sondland show up and set a precedent for cooperation with an inquiry they have strenuously argued is illegitimate.
On Tuesday morning, Mr. Trump attacked the impeachment inquiry.
“I would love to send Ambassador Sondland, a really good man and great American, to testify,” he wrote on Twitter, “but unfortunately he would be testifying before a totally compromised kangaroo court, where Republican’s rights have been taken away.”
Robert Luskin, Mr. Sondland’s lawyer, said in a statement that as a State Department employee, his client had no choice but to comply with the administration’s direction. He said Mr. Sondland had been prepared and happy to testify, and would do so in the future if allowed.
“Ambassador Sondland is profoundly disappointed that he will not be able to testify today,” Mr. Luskin said. “Ambassador Sondland believes strongly that he acted at all times in the best interests of the United States, and he stands ready to answer the committee’s questions fully and truthfully.”
Mr. Sondland has become enmeshed in the burgeoning scandal into how the president sought to push the Ukrainians to investigate his political rivals. Although Ukraine is not in the union, Mr. Trump instructed Mr. Sondland — a wealthy hotelier and campaign contributor — to take a lead in relations between the Trump administration and the country. Democrats consider him a key witness to what transpired between the two countries.
Mr. Sondland interacted directly with Mr. Trump, speaking with the president several times around key moments that House Democrats are now investigating, including before and after Mr. Trump’s July call with the new Ukrainian president, Volodymyr Zelensky. The president asked Mr. Zelensky on the call to do him “a favor” and investigate the business dealings of Vice President Joseph R. Biden Jr.’s son and a conspiracy theory about Ukrainian meddling in the 2016 election.
Text messages provided to Congress last week showed that Mr. Sondland and another senior diplomat had worked on language for a statement they wanted the Ukrainian president to put out in August that would have committed him to the investigations sought by Mr. Trump. The diplomats consulted with Mr. Trump’s personal lawyer, Rudolph W. Giuliani, about the statement, believing they needed to pacify him in order to allow the United States to normalize relations with the Ukrainians.
Mr. Sondland was also involved in a back and forth with top American diplomats to Ukraine over text last month demonstrating that some senior State Department officials believed that Mr. Trump may have been holding up $391 million in security aid for Ukraine as leverage for getting its leaders to conduct the investigations Mr. Trump wanted.
“As I said on the phone, I think it’s crazy to withhold security assistance for help with a political campaign,” William B. Taylor Jr., a top American official in Ukraine, wrote in one exchange in early September.
After receiving the text, Mr. Sondland called Mr. Trump, who asserted it was false.
“Bill, I believe you are incorrect about President Trump’s intentions,” Mr. Sondland wrote in the messages. “The President has been crystal clear no quid pro quo’s of any kind.”
Mr. Sondland added: “I suggest we stop the back and forth by text.”
There have been conflicting accounts of Mr. Sondland’s views, however. Senator Ron Johnson, Republican of Wisconsin, told The Wall Street Journal last week that Mr. Sondland had told him in August that the release of the aid was contingent upon Ukraine opening the investigations. Mr. Johnson was alarmed and asked Mr. Trump if there was a quid pro quo involved. The president adamantly denied it, he said.