NEW YORK (AP) — Newt Gingrich thanked supporters Tuesday, a day before he officially leaves the Republican presidential race, and pledged to work hard to prevent the "genuine disaster" he says would come from re-electing President Barack Obama.

Gingrich says in a video message posted on his website that he will close his campaign on Wednesday.

"Your help was vital," he tells supporters in the nearly two-minute video.

The former House speaker doesn't mention Mitt Romney, the all-but-certain GOP presidential nominee, but said he would continue working to deny Obama a second term.

Gingrich has scheduled his announcement for Wednesday afternoon in Arlington, Va.

After finishing poorly in five Northeastern primaries held last week, Gingrich indicated he would leave the race.

He won only two contests — in South Carolina and Georgia, which he represented in Congress for 20 years.

His campaign also has reported being more than $4 million in debt.