Transcripts released Friday by the House Intelligence Committee contain accounts by two White House officials of an effort by President Donald Trump and his close associates to pressure Ukrainian President Volodymyr Zelenskiy into publicly undertaking politically charged investigations in exchange for a meeting between the two leaders.

“The demand was, in order to get the White House meeting, they had to deliver an investigation,” Lt. Col Alexander Vindman, the top Ukraine expert on the National Security Council (NSC), told congressional investigators in a closed-door deposition on October 29. The investigation that Trump wanted, he said, was “into the Bidens.”

An impeachment inquiry is underway amid allegations that Trump leveraged his position to push the Ukrainian leader to announce a probe into Burisma, an energy company where former Vice President Joe Biden’s son sat on the board, as well to investigate whether Ukraine interfered in the 2016 U.S. presidential election on behalf of former Secretary of State Hillary Clinton.

On July 10, Ukrainian officials—eager to bolster their relationship with the U.S.—expressed interest in the meeting between Zelenskiy and Trump. According to Vindman’s account, Gordon Sondland, the ambassador to the European Union, “started to speak about Ukraine delivering specific investigations in order to secure the meeting with the President.” National Security Adviser John Bolton ended the meeting early and allegedly reprimanded him.

Vindman’s testimony further complicates matters for Sondland, who initially told congressional investigators in his sworn deposition that he had no knowledge of any attempts to push Ukraine into conducting the politically motivated probes. He revised those remarks on November 4, writing that other congressional testimonies had “refreshed [his] recollection.” He says he now recalls telling a top Zelenskiy adviser on September 1 that the continuation of military aid, which the Trump administration had abruptly frozen over the summer, “would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks.” Per the congressional testimony, that “anti-corruption statement” referred to the two public investigations that Trump sought from Zelenskiy.

Fiona Hill, Trump’s former Russia adviser, confirmed Vindman’s telling in her separate closed-door deposition. “Ambassador Sondland, in front of the Ukrainians, as I came in, was talking about how he had an agreement with Chief of Staff Mulvaney for a meeting with the Ukrainians if they were going to go forward with investigations.” Vindman also drew the connection to Mulvaney, who chose not to show up to testify on Friday despite a congressional subpoena.

Then came the much-discussed July 25 call between Trump and Zelenskiy, where the former asked the latter to initiate the corruption investigations into the Bidens. Per Vindman’s testimony, Zelenskiy specifically agreed to look into Burisma, but the White House replaced that with “the company you mentioned” when it released a summary of the conversation to the public.

“It was a demand that the Ukrainians deliver these investigations in order to get what they have been looking for, which is the presidential meeting,” Vindman testified.

Hill, who was also on the line, said that she was “quite shocked” at Trump’s push to have a foreign power commence investigations targeting Biden, his potential Democratic opponent in the 2020 election, and Hillary Clinton, his foe in the 2016 race.

“It was pretty blatant” that Trump was trying to orchestrate an exchange, Hill testified. “I found that I couldn’t really explain that away with an alternate explanation.”