Donald Trump is using a State Department inspector general report on Hillary Clinton's private email server to convince voters his opponent "cannot be allowed in the White House."

The presumptive Republican presidential nominee called the report a "disaster" for the Clinton campaign in a tweet Thursday morning.

Trump's attack on Clinton's "temperament" is an attempt to turn the tables on her, because Clinton has made questions about Trump's temperament central to her strategy of portraying him as too "risky" to be trusted in the White House.

The IG report, received by lawmakers on Wednesday, and claimed that "at a minimum, Secretary Clinton should have surrendered all emails dealing with Department business before leaving government service and, because she did not do so, she did not comply with the Department's policies that were implemented in accordance with the Federal Records Act."

Furthermore, the report noted that Clinton failed to inform some State Department staffers about her use of a private email server as secretary of state and that "no knowledge of approval or review by other Department staff" of the server, despite her repeated claim that she received permission to use the homebrew server.

Clinton declined to be interviewed by the inspector general, while former Secretaries of State Madeleine Albright, Colin Powell and Condoleezza Rice each complied.

Trump also referenced the report to his supporters on Wednesday during a campaign rally in Anaheim, Calif. "She had a little bad news today, as you know from some reports that came down," he said. "Not so good. inspector general's report — not good! But I want to run against Hillary. I just want to run against her."