Newt Gingrich (creative commons)

“Newt and I agreed that the analogy is December 1941,” Gingrich's campaign director Michael Krull said in a message posted on Facebook. “We have experienced an unexpected set-back, but we will re-group and re-focus with increased determination, commitment and positive action. Throughout the next months there will be ups and downs; there will be successes and failures; there will be easy victories and difficult days - but in the end we will stand victorious.”

Gingrich's failure to qualify for the ballot in Virginia could be a major blow to his campaign, as recent polls of likely Republican voters in the state showed him leading the other candidates.

Krull acknowledged the setback, but said the campaign would rebound: "Newt and I have talked three or four times today and he stated that this is not catastrophic - we will continue to learn and grow. Remember that it was only a few months ago that pundits and the press declared us dead after paid consultants left," he said in the Facebook post.

Gingrich, along with Rick Perry, Michele Bachmann, Jon Huntsman and Rick Santorum, failed to collect the 10,000 signatures necessary to appear on the Virginia ballot. The deadline to turn in the signatures was 5 p.m. on Thursday.

Only two Republican presidential candidates - Mitt Romney and Ron Paul - qualified for the state's primary, which will be held on Super Tuesday, March 6.