(CNN) The US Department of Energy has released a new batch of documents related to its former Secretary Rick Perry and Ukraine.

The public records release Tuesday evening -- initially given to transparency group American Oversight as a part of a Freedom of Information Act lawsuit and then released publicly by the group -- marks the first set of documents the Department of Energy has made public that could flesh out impeachment allegations against President Donald Trump, as well as possibly offer a window into one of the highest ranking administration officials involved in the Ukraine quid pro quo aside from Trump himself.

The documents show how the Department of Energy pushed for energy reform and even applauded Ukraine for its handling of corruption in May 2019, when Perry led a delegation to meet new Ukrainian President Volodymyr Zelensky.

Yet the new set of documents, coming after the House sought and couldn't get them and many more, don't cover how -- almost immediately upon his return to the US -- Trump supplanted that approach by pushing Perry in another direction: to work with his personal attorney Rudy Giuliani and to pursue a different, more specific Ukrainian corruption crackdown, one that would help Trump politically, according to several State Department witnesses who testified to the House.

Evidence related to that later push -- of which Perry was a central player, other administration officials said under oath -- isn't included in the release on Tuesday, which largely covers documents used to brief Perry before his trip abroad.

The Department of Energy plans to release more documents related to Perry in February and March.

On one page of Perry's briefing book for the Zelensky meeting, there's a benign mention of anti-corruption initiatives: "The United States and the European Union stand ready to work with you to ensure that change and reform can be implemented. But you must be committed to make the hard choices on corruption and good governance reforms."

Perry was in touch with former national security adviser John Bolton, making this document release especially noteworthy given the discussions about Bolton's possible testimony in the Senate impeachment trial.

The set of documents includes Perry's briefing book in advance of his May trip, with State Department officials, to meet with Zelensky, a trip that played a sizable role in Trump's pressure campaign to dangle a meeting with Zelensky in exchange for political help.

The Department of Energy stonewalled attempts from House impeachment investigators to gain documents from Perry, saying the request for documents lacked "any pretense of fairness." The White House also blocked his former chief of staff Brian McCormack from testifying. Those refusals became part of the House's obstruction of Congress charge against the President.

Perry left the Energy Department in early December. He announced he planned to leave shortly after news broke of a whistleblower's complaint about the Ukraine quid pro quo.

Impeachment witnesses have described Perry as one of the main players in soliciting political help from Ukraine on Trump's behalf.

He was involved in the main discussions where Trump or those working on Trump's behalf talked about requesting political help from Zelensky prior to the Presidents' July 25 call. He's one of the so-called "Three Amigos," alongside then-ambassador Kurt Volker and American Ambassador to the European Union Gordon Sondland, who coordinated Trump's efforts with Ukraine.

He allegedly was in communication with Giuliani early about Trump's political wishes in Ukraine, and he pushed his own ties to the energy industry with Zelensky. He was also in touch with acting White House chief of staff Mick Mulvaney, Secretary of State Mike Pompeo and others the House unsuccessfully sought details from during the impeachment inquiry, according to some of the witnesses and the House's findings.

Sondland testified in his opening statement to the House (and other witnesses backed up with their own testimony): "Secretary Perry, Ambassador Volker and I worked with Mr. Rudy Giuliani on Ukraine matters at the express direction of the President of the United States."

Sondland was one of the most damaging witnesses for Trump, spelling out the quid pro quo Trump sought with Ukraine.

While the administration has stonewalled the House from getting documents like these, transparency groups and news organizations gradually have pried emails and other administration communications related to Ukraine from agencies through public records lawsuits. The release on Tuesday went to the group American Oversight, after the Department of Energy agreed to produce documents the group sought under the Freedom of Information Act. It's the first of three scheduled releases from the Energy Department as part of the lawsuit.

This story has been updated with more information on the contents of the documents.