Gingrich officially dropped out of the presidential race at an event in northern Virginia on Wednesday but refrained from actually endorsing the GOP's presumptive nominee Mitt Romney.

"Today I am suspending my campaign. However, suspending the campaign does not mean suspending citizenship." Gingrich went on in a long speech to talk about numerous subjects, including his infamous moon colony comment. However, the one subject he steered away from for the most part was Mitt Romney.

"This is not a choice between Mitt Romney and Ronald Reagan," said Gingrich, in what was not exactly a full throated endorsement. "This is a choice between Mitt Romney and the most radical leftist president in American history."

However, Gingrich has said that he is committed to help the effort to oust President Obama

The Obama Campaign is out with a new web ad asking the question, "Newt Gingrich is throwing his support behind Mitt Romney?" The ad goes on to show numerous times during the campaign when Gingrich attacked Romney, including one on-camera instance where the former House Speaker was asked if he was calling Romney a liar, to which Gingrich answered simply, "Yes."

The Romney camp fired back. "President Obama and his campaign will do anything to avoid talking about his record of failure - and they certainly don't want to talk about his plans to increase taxes on entrepreneurs and small businesses," said Romney Campaign Spokesperson Amanda Henneberg. "Instead of working to fix the economy, President Obama prefers to point fingers and launch political attacks."

Jake Gibson is a producer working at the Fox News Washington bureau who covers politics, law enforcement and intelligence issues.