President Donald Trump wanted his Ukrainian counterpart to declare publicly that he was embarking on an investigation into Hunter Biden’s work in Ukraine.

That’s according to William Taylor, America’s top diplomat to Ukraine, who also told Congress on Tuesday that Ukraine’s president agreed to make the announcement on CNN.

Taylor, according to a copy of his opening statement obtained by The Daily Beast, said that Trump told Gordon Sondland, his ambassador to the European Union, that Ukrainian President Volodymyr Zelensky had to “clear things up and do it in public” as Ukraine waited for the U.S. to release a shipment of military aid.

Tim Morrison, who helms the National Security Council’s Eurasia desk, told Taylor about a phone call between Trump and Sondland. “According to Mr. Morrison… President Trump did insist that President Zelensky go to a microphone and say he is opening investigations of Biden and 2016 election interference, and that President Zelensky should want to do this himself.”

According to Taylor, the call gave Morrison a “sinking feeling.”

The NSC had a series of meetings about the decision to withhold military support from Ukraine, including meetings that included cabinet secretaries. “At every meeting, the unanimous conclusion was that the security assistance should be resumed, the hold lifted,” Taylor said. Mike Pompeo, CIA Director Gina Haspel, National Security Adviser John Bolton, and the secretary of defense tried to meet with Trump to urge him to release the assistance. “[S]uch a meeting was hard to schedule, and the hold lasted well into September,” Taylor said.

NSC officials later told him that acting Chief of Staff Mick Mulvaney directed that the aid be withheld, and that he “maintained a skeptical view of Ukraine.”

Taylor also described a dramatic July 10 White House meeting between Ukrainian officials, Bolton, and Sondland. NSC officials described the meeting to Taylor, who was not present for it. According to Taylor, Sondland told Ukrainians that “investigations” were connected to their quest for an Oval Office meeting between Trump and Zelensky. The comment “so irritated Ambassador Bolton that he abruptly ended the meeting,” told the officials to stay away from domestic politics, and directed one of the officials to “brief the lawyers.”

In addition, “Ambassador Sondland said that he had talked to President Zelenskyy and Mr. Yermak and told them that, although this was not a quid pro quo, if President Zelensky did not 'clear things up' in public, we would be at a ‘stalemate.’ I understood a ‘stalemate’ to mean that Ukraine would not receive the much-needed military assistance,” Taylor told Congress.

Sondland told Zelensky that when he discussed investigating Hunter Biden’s company and 2016 election meddling with Trump, he should promise to “leave no stone unturned.”

The attempt to pressure the Ukrainian president into a public declaration of an investigation into Biden is one of many revelations in Taylor’s testimony on Tuesday. That testimony is currently underway.

Taylor also cast doubt on President Trump’s repeated descriptions of his July 25 call with President Zelensky as “perfect,” an opinion some of his aides did not share. Taylor had not been listening in on the call and did not receive a readout but he said that Tim Morrison, the top Eurasia staffer on the National Security Council, told him the call in which Trump asked Zelensky to investigate the Bidens, “could have been better.”

Bolton opposed the idea of a Trump/Zelensky call and, per Taylor, thought it “would be a disaster.”

Zelensky told both Taylor and Volker afterwards that he was “happy with the call but did not elaborate."

When the White House finally released a rough transcript of the call, however, Taylor said Ukrainian officials were “livid” and had been given “virtually no notice” that it would be published.

Taylor described two different—and conflicting—channels of diplomacy between the U.S. and Ukraine: the official channel and an unofficial channel, which included Volker, Sondland, and Trump’s personal attorney Rudy Giuliani. Some members of the unofficial channel tried to push the Ukrainians to investigate the company where Hunter Biden was a board member.

Taylor took over as chargé d'affaires to Ukraine in May after a whisper campaign lead by Rudy Giuliani prompted Trump to recall Ambassador Marie Yovanovitch. A career diplomat, Taylor wasn’t among the “three amigos”—Energy Sec. Rick Perry, Special Representative Kurt Volker, and Sondland—deputized by Trump to take the lead on the U.S.-Ukraine relationship. He told Congress he was concerned about the direction of Ukraine policy before taking the job.

Taylor said he accepted the job of chief diplomat with hesitation, as he was “worried” about rumors of Giuliani’s back-channel diplomacy with Ukrainian officials and felt Yovanovitch had been “treated poorly” and “caught in a web of political machinations both in Kyiv and in Washington.”

As Sondland and Volker kept pressing Zelensky over the summer, Taylor appeared to be a voice of caution, if not open hostility, towards the effort to squeeze Ukrainian officials into a politically tinged corruption investigation. In July, he told the two that “Zelensky is sensitive about Ukraine being taken seriously, not merely as an instrument in Washington domestic, reelection politics,” according to text messages released the House Foreign Affairs Committee.

Taylor said that the weight of the Trump administration’s decision to halt military aid to Ukraine as part of the apparent pressure campaign weighed on him during a visit to the front lines of Ukraine’s war with Russian-backed rebels. “More Ukrainians would undoubtedly die without the U.S. assistance,” Taylor recalled in his testimony.

As the Trump administration put the brakes on military aid designed to hold off Russia’s occupation of Eastern Ukraine, Taylor grew more resistant to the pressure campaign. In a September text message to Sondland, he called it “crazy” to withhold aid in exchange for domestic political favors.

In his statement on Tuesday, Taylor stood by that characterization. “I believed that then, and I still believe that.”