UPDATED Feb 2, 11:09 a.m. ET
With just days to go before Nevada Republicans head to the polls to choose who they want to take on President Obama in November, reality show host Donald Trump is injecting himself into the race.
Trump's office announced Wednesday that he would make a major announcement Thursday morning in Las Vegas, without providing details of what he would say. Trump's reality show, "The Apprentice," begins a new season February 12.
Two sources close to Newt Gingrich told CBS News late Wednesday night that the publicity savvy businessman plans to endorse the former House speaker in his bid for the Republican presidential nomination. Nevada holds its caucus Saturday.
But CNN reported Thursday morning that Trump would endorse rival Mitt Romney.
Asked after that report was published if they continued to expect Trump would endorse Gingrich, two sources close Gingrich conceded that Trump has his own agenda. And two sources close to Romney told CBS News late Thursday morning Trump would, in fact, endorse the former Massachusetts governor.
The CBS television station in Las Vegas, KLAS-TV, reported earlier Wednesday that Trump would endorse Gingrich, citing "sources."
The businessman and the candidate were both coy about the announcement.
"We'll see tomorrow, have some fun," Trump told CBS News/National Journal when asked very early Thursday if he planned to make an endorsement. Asked about Gingrich, he declined comment "right now," as he arrived at his hotel in Las Vegas.
Shortly after news of an unspecified "announcement" was made Wednesday, but before the endorsement was confirmed by CBS News and other media outlets, Gingrich said he did not know Trump's plans.
"I have no idea what the Donald is going to do. He is always interesting, and I don't know of anybody who does a better job of getting attention by announcing that he will presently announce something," Gingrich said.
On CBS' Face the Nation Sunday, Trump had kind words for Gingrich.
"He's got great ideas. He's very smart, he's very tough and he is a great debater," Trump said, adding that the two most recent debate performances were not his best efforts. Gingrich was widely seen as fumbling in both Florida appearances before Tuesday's primary, which he lost to former Massachusetts Gov. Mitt Romney by a large margin.
Trump has toyed with jumping in the presidential race himself as a third party candidate after his NBC reality television series, "The Apprentice," ends its season in May.
But he said he would only jump in the race as an independent that if the Republican candidate he likes gets fired by the voters.
"If that candidate would get the nomination, I absolutely would not run," Trump said, adding that if his preferred choice loses, he would consider himself a "free agent." He decided against a bid last year after attacking Mr. Obama relentlessly about releasing the so-called "long-form" of his birth certificate from the state of Hawaii.
It is not clear how much Trump's endorsement would help Gingrich going forward, especially since Romney is a heavy favorite in Nevada. Romney beat Texas Rep. Ron Paul by close to 40 percentage points in Nevada in 2008.
Still, Gingrich could get an infusion of cash following Trump's announcement.
Billionaire casino magnate Sheldon Adelson, who has already given $10 million to the super PAC supporting Gingrich, had dinner plans with Gingrich this week, a source familiar with the meeting told CBS News.
Trump, who has also been involved in the gambling industry, likes to be the center of attention and does not like to be upstaged.
Trump's endorsement is not the only one for Republicans hoping to win Nevada in three days time. Failed Senate candidate Sharron Angle, a favorite of the conservative Tea Party wing of the party, plans to endorse former Pennsylvania Sen. Rick Santorum, National Review reported Wednesday.
Additional reporting by Laura Strickler and Lindsey Boerma.