The third-highest official at the U.S. State Department told House impeachment investigators Wednesday that there is no link between the U.S. freezing aid to Ukraine and President Donald Trump’s requests for investigations, Rep. Mark Meadows (R-NC) declared.

David Hale, the undersecretary of state for political affairs, testified behind closed doors. His testimony echoed comments by his two superiors — Secretary of State Mike Pompeo and Deputy Secretary of State John Sullivan — who have denied the alleged quid pro quo at the center of the impeachment inquiry. Neither Pompeo nor Sullivan have testified in the impeachment inquiry.

“Just finished with Ambassador David Hale’s testimony, the number 3 at the State Department, and a distinguished public servant,” Meadows, who witnessed Hale’s testimony, wrote on Twitter Wednesday. “He made a compelling case that there was absolutely no linkage between [the] suspension of military aid and political investigations.”

Just finished with Ambassador David Hale's testimony, the number 3 at the State Department and a distinguished public servant. He made a compelling case that there was absolutely no linkage between suspension of military aid and political investigations. — Mark Meadows (@RepMarkMeadows) November 6, 2019

House Democrats pursuing the partisan impeachment probe are trying to find out whether Trump abused his power by holding up military aid to Ukraine to allegedly pressure Kiev to launch investigations that could have benefited the U.S. president politically.

White House hopeful Joe Biden and his son Hunter are linked to one of the corruption investigations sought by Trump. Both Joe and Hunter Biden deny any wrongdoing.

The Trump administration ended up releasing the aid to Ukraine on September 11 without the Eastern European country having to do anything in return.

Hale is the first witness to show up for his testimony in the impeachment probe this week. Several White House witnesses have refused to testify, even under subpoena, after the White House directed them to skip their deposition.

Energy Secretary Rick Perry, Acting Office of Management and Budget (OMB) Director Russ Vought, and Ulrich Brechbuhl, the State Department counselor, declined to testify Wednesday.

Hale reportedly testified for about six hours. Democrats are beginning to wrap up the closed-door portion of their investigation, saying they will hold public hearings next week.

The impeachment inquiry came after a so-called “whistleblower” issued a complaint accusing Trump of coercing Ukraine to conduct the investigations in exchange for aid during a July 25 phone call with Ukrainian President Volodymyr Zelensky. The “whistleblower” lacked firsthand knowledge of the conversation.

Trump, Zelensky, and some impeachment probe witnesses have denied the “whistleblower’s” allegation of a quid pro quo, considered the crux of the investigation. Citing second-hand information, however, other witnesses have presumed that a quid pro quo took place in which Trump pushed Ukraine to investigate the Bidens and 2016 U.S. election interference in exchange for aid.

Pompeo has accused House Democrat impeachment investigators of harassing department employees by requesting their testimony.

Some State Department officials, meanwhile, have accused Pompeo of not doing enough to protect department employees during the ongoing impeachment probe.

On Wednesday, the Associated Press noted:

People familiar with the matter said Hale, the highest-ranking career diplomat in the foreign service, planned to say Secretary of State Mike Pompeo and other senior officials determined that publicly defending ousted Ambassador Marie Yovanovitch would hurt the effort to free up U.S. military assistance to Ukraine.

Some State Department officials have testified that they opposed the dismissal of Yovanovitch, which came at the behest of Trump. The U.S. president has the authority to remove any of his ambassadors.