Washington — The House released the transcript Monday from the closed-door testimony of David Holmes, a State Department official who overheard a recently revealed call that has become key to the impeachment inquiry against President Trump. Holmes will testify later this week.

In his opening statement, Holmes said he overheard Mr. Trump ask a top diplomat about the status of "investigations" into his political rivals on July 26 — one day after his now-infamous July 25 call with the president of Ukraine.

The existence of this July 26 call was revealed last week by William Taylor, the top U.S. diplomat in Ukraine who testified in public on Tuesday. Holmes, who is Taylor's aide, corroborated Taylor's account. It provides further support for the accusation that Mr. Trump committed a politically charged quid pro quo and withheld U.S. aid from Ukraine to pressure the foreign country to launch investigations that could help his reelection campaign.

Get Breaking News Delivered to Your Inbox

"I've never seen anything like this, someone calling the president from a mobile phone at a restaurant, and then having a conversation of this level of candor, colorful language. There's just so much about the call that was so remarkable that I remember it vividly," Holmes testified on Capitol Hill behind closed doors last week.

Read the full text of Holmes' testimony here:

Holmes said he was sitting near Gordon Sondland, the U.S. ambassador to the European Union, at a restaurant in Kiev and could hear him speaking to Mr. Trump, who said, "So, he's gonna do the investigation?" referring to Ukraine's president, Volodymyr Zelensky. Holmes testified that Sondland replied, "He's gonna do it" and added that Zelensky would do "anything you ask him to."

Holmes testified that the call was also unusual because such a call with the president would generally take place in a more secure setting, not on a cell phone. He noted that at least two of the three mobile networks in Ukraine are owned by Russian companies, and the U.S. generally assumes mobile communications in Ukraine are being monitored

David Holmes, a State Department official, arrives to appear in a closed-door deposition hearing as part of the impeachment inquiry at the US Capitol in Washington, D.C., on November 15, 2019. Olivier Douliery

Holmes recalled that Sondland later told him that "the president did not 'give a s**t about Ukraine.'" According to Holmes, Sondland said that only "big stuff matters" to the president, "like this Biden investigation that Giuliani is pushing."

There is no evidence to support the claims by Mr. Trump and his Republican allies that Joe or Hunter Biden engaged in corruption in Ukraine. While Joe Biden was vice president, his son Hunter was hired by a Ukrainian gas company.

Holmes also testified that Marie Yovanovitch, the former ambassador to Ukraine who testified last week, was as good at fighting corruption as anyone known for that, and said the smear campaign against her was obvious.

Rebecca Kaplan contributed reporting.