Republican presidential hopeful Newt Gingrich has hinted that he will suspend his campaign next week, according to US media reports.
The former House Speaker said he expected Mitt Romney, who won five primaries yesterday, to be the Republican nominee to contest the US presidential election.
During a campaign stop in North Carolina on Wednesday, Mr Gingrich all but conceded.
I do think it's pretty clear that Governor Romney is ultimately going to be the nominee, and well do everything we can to make sure that he is, in fact, effective."
The BBC reports that former Massachusetts Governor Romney has an unassailable lead in the race for the 1,144 delegates needed to secure the Republican nomination at the party convention in August.
Texas Congressman Ron Paul is the only other remaining candidate in the race, although he cannot win.
The eventual Republican nominee will take on President Barack Obama for the White House in an election on 6 November this year.