A White House national security official has reportedly been fired for posting insulting messages about top officials and Obama administration policies under an anonymous Twitter account.

Jofi Joseph, a nonproliferation expert on the National Security Council, was fired last week after it was discovered he was the author of the @natsecwonk Twitter feed, well-known inside the beltway for its snarky blasts about the Obama administration, the Daily Beast was first to report.

Joseph, who was recently part of the team working on negotiations with Iran over its nuclear program, has said that he deeply regrets the tweets.

"It has been a privilege to serve in this administration and I deeply regret violating the trust and confidence placed in me," Joseph told Politico. "What started out as an intended parody account of D.C. culture developed over time into a series of inappropriate and mean-spirited comments. I bear complete responsibility for this affair and I sincerely apologize to everyone I insulted."

The White House confirmed to ABC that Joseph no longer works in the administration but would not comment further.

Under the cover of his alias, Joseph took aim over two years at high-ranking administration officials and Republicans alike, slamming their intellect and criticizing their appearance.

"I'm a fan of Obama, but his continuing reliance and dependence upon a vacuous cipher like Valerie Jarrett concerns me," he once reportedly tweeted of the president's senior adviser.

Summing up his colleagues, he once reportedly tweeted, "'Has shitty staff.' #ObamaInThreeWords."

While insulting, the posts never included classified or sensitive information.