Newt Gingrich is planning to officially end his campaign for the US Republican presidential nomination with an announcement in Arlington, Virginia.
The former Speaker of the House of Representatives had indicated he would leave the race after he finished poorly in five north-eastern primaries last week.
On Tuesday, Mr 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 said would come from re-electing President Barack Obama, but did not mention Mitt Romney, the all-but-certain Republican presidential nominee.
Mr Gingrich won only two state contests - in South Carolina and in Georgia, which he represented in Congress for 20 years.
His campaign has reported being more than £2.5 million in debt.