US media had reported earlier this week that Mr Trump would support Mr Gingrich, whose presidential campaign has been struggling since his upset victory over Mr Romney in South Carolina on January 21.
ABC - The real estate mogul, a former Republican presidential hopeful
himself, says he got to know the former Massachusetts governor during
several recent conversations.
He said he was impressed with Mr Romney's tough talk on China and was won over by his strong performance campaigning in Florida.
"I was very impressed by the last two debates," Mr Trump told reporters in Las Vegas.
Mr Trump, who announced he was leaving the Republican party two months ago, seems an unlikely choice for Republican kingmaker.
But the casino owner and reality television star is popular in Nevada, whose caucuses are coming up on February 4.
Mr Romney seemed to snatch Mr Trump's backing from his main rival, former House speaker Newt Gingrich.
media had reported earlier this week that Mr Trump would support Mr
Gingrich, whose presidential campaign has been struggling since his
upset victory over Mr Romney in South Carolina on January 21.
But Mr Trump's support could also backfire on Mr Romney, a day after
the wealthy former private equity executive gave a clumsy reminder of
the challenges he faces winning over voters hit by the economic
"I'm not concerned about the very poor, we have a safety net there," Romney told CNN.
"If it needs repair, I'll fix it." (Continues here)