U.S. Secretary of Defense Mike Esper joined several other Trump administration officials in bucking Tuesday’s subpoena deadline for impeachment inquiry documents requested by House Democrats.

In a letter to House Democrats, the Pentagon said it was unable to produce the documents “at this time,” Reuters reported.

U.S. Vice President Mike Pence, President Donald Trump’s private lawyer Rudy Giuliani, and Russell Vought, the acting director of the White House Office of Management and Budget (OMB), also defied subpoena deadlines to submit requested documents.

House Democrat leaders had given Esper and the other officials until Tuesday to submit the requested information.

The decision by officials to resist the subpoenas, however, comes as no surprise. In a letter to House Democrat leaders last week, the White House said it would not cooperate with the impeachment investigation. The White House has deemed the probe’s process “illegitimate.” In the letter, the White House all but dared House Democrats to vote to authorize the investigation.

Esper and the other officials echoed the White House’s position in their own letters. They wrote to House Democrats that they were not honoring the subpoena’s deadline because the probe is illegitimate.

On Tuesday, Reuters reported:

In a letter seen by Reuters, the Pentagon said the House of Representatives did not have a resolution authorizing an impeachment investigation, adding that it could not produce documents in the eight days it was given to comply with the subpoena.

The letter reportedly declared:

The Department is unable to comply with your request for documents at this time. Nevertheless, the Department respects the oversight role of the appropriate committees of Congress, and stands ready to work with your committees should there be an appropriate resolution of this matter.

Over the weekend, Esper said he would cooperate with his subpoena. The Pentagon chief, however, did not explicitly commit to honoring Tuesday’s deadline to provide documents.

“I don’t know the status of what that document preparation is, what restrictions we may have internally with regard to releasing them, the White House has a say on the release of documents as well,” he told Fox News Sunday‘s Chris Wallace.

House Democrats warned Esper against not complying with the subpoena in the October 7 letter requesting the documents.

Consistent with warnings for other Trump administration officials, the Democrats cautioned Esper:

Failure or refusal to comply with the subpoena, including at the direction or behest of the President or the White House, shall constitute evidence of obstruction of the House’s impeachment inquiry and may be used as an adverse inference against you and the President.

The Democrat-led Committees on Oversight and Reform, Intelligence, and Foreign Affairs are conducting the impeachment probe.

A “whistleblower” allegation that Trump attempted to coerce Ukraine into investigating Joe Biden and his son, Hunter, is at the center of the investigation.