By James Oliphant
Republican presidential front-runner Donald Trump has won another high-profile endorsement, with retired neurosurgeon Ben Carson becoming the second former Republican candidate to back him in the race for the White House.
"We buried the hatchet. That was political stuff," Mr Carson said during a joint appearance with the billionaire businessman at a Friday (local time) news conference at Trump's Mar-a-Lago Club resort Palm Beach, Florida.
"I have found in talking with him, that there's a lot more alignment, philosophically and spiritually, than I ever thought that there was," added Mr Carson.
The latest endorsement for Mr Trump followed a CNN-hosted Republican debate in Miami on Thursday night. It gives the New York real estate magnate a boost just days before crucial nominating contests in the battle to be the party's presidential candidate for the November 8 election.
Republican primaries in five states - including Florida and Ohio - on March 15 will be critical for Mr Trump to cement his lead, and to determine whether US Senator Marco Rubio of Florida and Ohio Governor John Kasich will be able to continue with their increasingly long-shot candidacies.
Trump told Friday's news conference that Mr Carson had not asked for any formal role, but praised his former rival's ideas on education.
Mr Carson, who had some support last year in opinion polls but whose campaign failed to garner backing in the early nominating contests, dropped out of the race last week.
On Friday he said that Mr Trump is sincere in his talk about making America great again, and that he is on board to help him.
Another former candidate, New Jersey Governor Chris Christie, announced last month he was backing Mr Trump.
In the process, he has alarmed many in the Republican establishment with his brash style and statements about immigrants, Muslims and free trade.
Candidates need to reach 1237 delegates in primary contests to win the nomination and Mr Trump's closes rival is Ted Cruz, a US senator from Texas. Trump has 459 delegates, followed by Mr Cruz at 360, Rubio at 152, and Kasich at 54, according to the Associated Press.
For his part, Mr Rubio said in a round of television interviews Friday morning he was still in position to win Florida's winner-take-all contest next week. Voters in his home state who do not want Mr Trump as the Republican nominee should support him, he said.