WASHINGTON (Reuters) - Two officials who had been asked to testify in the impeachment investigation of U.S. President Donald Trump have agreed to provide depositions, an official with a Democratic-led House of Representatives committee said on Tuesday.

Former U.S. Ambassador to Ukraine Marie Yovanovitch will give a deposition on Oct. 11, according to the committee official who spoke on condition of anonymity. Trump’s former special representative for Ukraine, Kurt Volker, will appear before the panel on Thursday, the official said.

Following a whistleblower complaint last week, Democrats are looking into Trump’s request to Ukrainian President Volodymyr Zelenskiy during a July 25 phone call to investigate a domestic political rival, former Vice President Joe Biden. Biden is a leading Democratic contender in the contest to run against Republican Trump in the 2020 election.

The unidentified whistleblower is said to be an intelligence agent who accused Trump of soliciting foreign interference for his personal political benefit.

Earlier on Tuesday, U.S. Secretary of State Mike Pompeo pushed back on House Democrats’ efforts to get the depositions from State Department officials, accusing the lawmakers of bullying and intimidation.

The officials “may not attend any interview or deposition” without executive branch counsel present to control disclosure of confidential information, Pompeo wrote in a letter to House Foreign Affairs Committee Chairman Eliot Engel.

Engel and two other Democratic committee chairmen issued a statement accusing Pompeo of “stonewalling” the impeachment inquiry, and called him a “fact witness” in the investigation, based on media reports that he had listened in on Trump’s call with Zelenskiy.

“He should immediately cease intimidating department witnesses in order to protect himself and the president,” Engel and Representatives Adam Schiff and Elijah Cummings said.

There was no immediate word on whether three other officials had agreed to requests to appear before the committees. They are Deputy Assistant Secretary of State George Kent, State Department Counselor T. Ulrich Brechbuhl and U.S. Ambassador to the European Union Gordon Sondland.

The State Department did not immediately respond to a request for comment.

The State Department’s inspector general, Steve Linick, will give an urgent briefing on Wednesday to staff members from several House and Senate committees about documents obtained from the department’s Office of the Legal Adviser related to the State Department and Ukraine, a source familiar with the briefing said. The briefing was requested by Linick.

RESIGNATION

Volker resigned last week after the whistleblower named him as one of two U.S. diplomats who followed up with Ukrainian officials a day after the Trump-Zelenskiy call.

The call occurred after Trump froze nearly $400 million in aid intended to help Ukraine deal with an insurgency by Russian-backed separatists. Zelenskiy agreed during the call to investigate Biden and his son Hunter and expressed interest in buying more U.S. arms in the form of Javelin anti-tank missiles. Hunter Biden had served as a director of a Ukrainian gas company.

The funds were later provided and a U.S. congressional aide said on Tuesday that Ukraine had agreed to buy 150 Javelin missiles, made by Raytheon Co and Lockheed Martin Corp, in a deal worth $39 million. Leaders of congressional committees signed off on the sale in the past week under an informal review process for major international military sales.

The impeachment inquiry could lead to approval of articles of impeachment - or formal charges - against Trump in the House. That would lead to a trial in the Senate on whether to remove him from office. But the president’s fellow Republicans control that chamber and have shown little appetite for removing him.

Pompeo, who is in Italy for a three-day trip, objected to Engel’s request for the officials to be made available for depositions.

FILE PHOTO: U.S. Secretary of State Mike Pompeo attends a lunch hosted by Chinese Foreign Minister Wang Yi with his counterparts of the permanent five veto-wielding members of the U.N. Security Council in New York, U.S., September 26, 2019. REUTERS/Yana Paskova

In a letter posted on Twitter, Pompeo told Engel: “I am concerned with aspects of your request that can be understood only as an attempt to intimidate, bully and treat improperly the distinguished professionals of the Department of State, including several career Foreign Service Officers, whom the committee is now targeting.”

Pompeo expressed “significant legal and procedural concerns” and said he viewed a committee letter to the officials as a “request for a voluntary appearance.” Pompeo said the announced dates for the depositions did not provide enough time for preparation. He also said his department would respond to a Foreign Affairs Committee subpoena by Friday.

He said records that have been requested are subject to restrictions relating to classified information and other executive branch privileges. Pompeo added that there was no legal basis for the committee’s assertion that a failure to appear would constitute evidence of obstruction.

Pompeo said he would use “all means at my disposal to prevent and expose any attempts to intimidate the dedicated professionals” at the State Department.

‘EVIDENCE OF OBSTRUCTION’

Pompeo’s letter marked the latest bid by Trump’s administration to avoid providing House Democrats testimony and documents relating to numerous investigations of the president. Democrats have accused Trump of a policy of stonewalling legitimate congressional inquiries.

“Any effort to intimidate witnesses or prevent them from talking with Congress - including State Department employees - is illegal and will constitute evidence of obstruction of the impeachment inquiry,” the three Democratic chairmen said.

Trump asked Zelenskiy to investigate Biden and his son in coordination with U.S. Attorney General William Barr and Trump’s personal lawyer Rudy Giuliani.

Trump continued on Tuesday to assail the impeachment inquiry and defend his call with Zelenskiy. The president asked on Twitter: “Why aren’t we entitled to interview & learn everything about the Whistleblower, and also the person who gave all of the false information to him.” Trump also wrote that Schiff should be “brought up on charges.”

A senior Republican senator, Chuck Grassley, came to the defense of the whistleblower.

“This person appears to have followed the whistleblower protection laws and ought to be heard out and protected,” Grassley said in a statement.

White-collar defense lawyer Jon Sale, who served as an assistant special prosecutor in the 1970s Watergate political scandal, said on Tuesday he would be representing Giuliani with the congressional inquiries.