The Seattle technology giant is one of the lone holdouts among major technology companies.
Google, Facebook, Twitter and other leading Silicon Valley companies have publicly disclosed the racial and gender breakdown of employees in recent months.
The reports have shown what many have long suspected, that the technology industry is overwhelmingly white, Asian and male.
Jackson said he telephoned CEO Jeff Bezos on Tuesday to reiterate his appeal that Amazon.com release its numbers.
Jackson first asked Amazon to publicly disclose its diversity statistics in a letter to Bezos in May.
