Perez is expected to make the announcement on a conference call with state party chairs, according to a source with knowledge of his planning cited in a CNN report.
The call was announced in an email sent Wednesday morning to supportive and neutral party chairs and vice chairs inviting them to an "informal discussion" about making the Democratic Party "more inclusive and one that represents all Americans," as quoted by Politico.
White House press secretary Josh Earnest noted Wednesday that President Barack Obama "thinks very highly of Secretary Perez" but said he doesn't expect the President to endorse any candidate.
"He is somebody who has served at the Department of Labor for three or four years now, and he has been instrumental in advancing some executive actions President Obama has prioritized," Earnest said, as quoted by CNN. "But as I've said before, I don't anticipate a situation in which the President forcefully endorses a candidate in the DNC chair's race."