Jofi Jospeph has been fired from his post as non-proliferation director at the National Security Council after using to a Twitter account to criticize the Obama administration, the Associated Press reported.
The Twitter account (@natsecwonk) has since been deleted.
The 40-year-old staffer, who had participated in nuclear negotiations with Iran, was fired a week ago after a month-long investigation by White House officials to uncover who was behind the account, Politico reported.
"It has been a privilege to serve in this Administration and I deeply regret violating the trust and confidence placed in me," Joseph said in an email to Politico.
Before joining the Obama administration, Joseph worked for Senator Bob Casey and Joe Biden in the State Department on Capitol Hill, The Daily Beast reported.
"What started out as an intended parody account of DC culture developed over time into a series of inappropriate and mean-spirited comments," Joseph wrote. "I bear complete responsibility for this affair and I sincerely apologize to everyone I insulted."
The tweets ranged from criticism of Secretary of State Hillary Clinton and other top officials, like Ben Rhodes who Joseph accused in tweets are dodging questions related to Benghazi, according to Politico.
"So when will someone do us the favor of getting rid of Sarah Palin and the rest of her white trash family? What utter useless garbage," one of his tweets read.
Another criticized Liz Cheney's and Mitt Romney's wife weight and choice of style, BBC News reported.
"I'm a fan of Obama, but his continuing reliance and dependence upon a vacuous cipher like Valerie Jarrett concerns me," another tweet read, according to the Daily Beast.
According to The Daily Beast, White House officials and administration are unsympathetic with Joseph, and feel he "betrayed their confidence while taunting them."
Politico has reported that during the investigation of the first Twitter handle, officials suspected Joseph had another Twitter account (@dchobbyist) which tweeted about racy sexual encounters, escort services and the inner workings of the State Department. Joseph didn't respond to a request for comment on the second account.
