By THE ASSOCIATED PRESS

WASHINGTON — Newt Gingrich is planning to officially end his campaign for the Republican presidential nomination with an announcement Wednesday in Arlington, Va.

The former House speaker had indicated he would leave the race after he finished poorly in five Northeastern primaries last week.

On Tuesday, Gingrich thanked supporters in a video message posted on his website, saying their "help was vital."

He pledged to work hard to prevent the "genuine disaster" he says would come from re-electing President Barack Obama, but did not mention Mitt Romney, the all-but-certain GOP presidential nominee.

The Obama campaign on Wednesday released an 80-second web video that compiled clips from interviews and debates during the Republican primary where Gingrich criticizes Romney on issues ranging from immigration to his tenure as a venture capitalist. "Newt Gingrich: Frankly, not Mitt Romney's biggest supporter," the ad states.

Gingrich won only two contests – in South Carolina and in Georgia, which he represented in Congress for 20 years. His campaign has reported being more than $4 million in debt.

