ARLINGTON, VA -- Newt Gingrich finally ended his presidential bid on Wednesday at a hotel just outside of the nation's capital, where he once led the Republican Party in Congress.

After a week of broadcasting his intent to suspend his campaign -- including the release of a video earlier this week thanking supporters and previewing the announcement -- Gingrich formally ended his bid for the Republican presidential nomination at an event his campaign had billed as a "press conference to announce suspension of campaign."

Benjamin Myers / Reuters

Republican presidential candidate Newt Gingrich speaks next to his wife Callista Gingrich as he suspends his presidential campaign May 2 in Arlington, Va.

"Today, I'm suspending the campaign but suspending the campaign does not mean suspending citizenship. Callista and I are committed to be active citizens. We owe it to America. We owe it to Maggie and Robert," Gingrich said, referring to his only two grandchildren, here in his home state of Virginia.

Once bitter rival of Mitt Romney, the presumptive GOP nominee, Gingrich vowed during his 26 minute speech to do whatever possible to beat Barack Obama but came short of actually endorsing Romney.

"I'm asked sometimes is Mitt Romney conservative enough. And my answer is simple: compared to Barack Obama? You know, this is not a choice between Mitt Romney and Ronald Reagan. This is a choice between Mitt Romney and the most radical leftist President in American history," Gingrich said while addressing roughly 100 members of the media inside the Hilton Hotel.

Romney said in a statement: "Newt Gingrich has brought creativity and intellectual vitality to American political life.  During the course of this campaign, Newt demonstrated both eloquence and fearlessness in advancing conservative ideas. Although he long ago created an enduring place for himself in American history, I am confident that he will continue to make important contributions to our party and to the life of the nation."

Gingrich’s spokesman said an official endorsement of Romney is still to come.

The news was far from surprising, given the way the former House speaker had been openly discussing the prospect of his exiting from the race ever since he finished poorly in the Delaware primary.

After finishing nearly 30 percent behind Mitt Romney in DE -- a state Gingrich frequented leading up to the election -- the speaker basically  gave two concession speeches while campaigning in North Carolina last week. He began calling Romney the "nominee" and said it was time to "be honest about what's happening in the real world as opposed to what you would like to have happen."

Gingrich's campaign had been considered virtually dead for weeks, though the winner of the South Carolina and Georgia primaries vowed to contest the nomination all the way through the Republican convention this summer in Tampa. Gingrich had assailed Romney's conservatism, and, to boot, President Obama's campaign circulated a video this morning featuring the ex-speaker's greatest hits against Romney.

That said, the month of May is far later in the election cycle than most political observers thought Gingrich would last. After suffering missteps in the launch of his campaign, most of Gingrich's senior staff quit on him last June.

Gingrich must also still work to erase millions of debts incurred during his campaign, mostly during its tail end.

But at today’s event, the Speaker seemed cheerful and unfazed by the $4 million hole he is in. He rather spent time talking about one of his most memorable ideas from the past 10 months – his proposed moon colony.
 
“My wife has pointed out to me approximately 219 times, give or take three, that the moon colony was probably not my most clever comment in this campaign. I thought, frankly, in my role providing material for Saturday night live it was helpful but the underlying key point is real,” Gingrich joked.