Donald Trump has awarded golfer Tiger Woods the Presidential Medal of Freedom, America's highest civilian honour.

The US president called recent Masters winner as a "true legend, an extraordinary athlete who has transformed golf and achieved new levels of dominance," before describing the litany of victories that Woods has obtained during his remarkable career and the injuries that almost derailed it.

The Masters was his 15th major golf championship and his 81st overall on the PGA Tour, both ranking second.

"He's a great guy," said Mr Trump. "He introduced countless new people to the sport of golf, from every background and walk of life. ... Tiger Woods is a global symbol of American excellence, devotion and drive."

Woods, wearing a blue suit was joined at the ceremony by his mother, Kultida, his two children, Sam and Charlie, his girlfriend, Erica Herman, and his caddie, Joe LaCava.

The 43-year-old became emotional as he spoke of his parents and thanked those who have supported him over the years.

"You've seen the good and bad, the highs and lows, and I would not be in this position without all of your help," he said.

The Medal of Freedom is given to individuals who have made "especially meritorious contributions to the security or national interests of the United States, to world peace, or to cultural or other significant public or private endeavours," according to the White House.

Presidents have complete discretion over whom they honour it.

However, the decision to give the award to Woods has raised questions about whether the president should be boosting the profile of a business associate of the Trump Organisation.

The US president has been using the golfer's cachet to attract fans to his properties for decades.

After Wood's first Masters victory in 1997, Mr Trump got him to turn up at his Taj Mahal casino in Atlantic City, New Jersey. The place was mobbed as 2,000 fans showed up told watch him walk down a 320-foot red carpet, some of them storming steel barricades to get a closer look.

Mr Trump has also struck business deals with Woods.

Golfers at Trump's club in Doral, Florida, can stay at the Tiger Woods Villa. At a ribbon cutting ceremony in 2014, Woods lavished praise on the future presidential candidate, calling changes he made to the club "phenomenal."

Woods designed an 18-hole course to be managed by The Trump Organisation in Dubai.

The Trump Organisation has "repeatedly demonstrated their ability to successfully manage unique, high-end courses and golf clubs, and this is no exception," Woods said in a 2018 interview in the company's in-house magazine.

Ethics officials have criticised Mr Trump for not selling off his assets completely and holding the money in a blind trust. Instead, he set up a trust to hold his assets, handed day-to-day management responsibilities to two sons and hired an ethics lawyer to vet business deals.

"You have to ask whether it's his true belief Tiger Woods deserves this award or whether he's doing it to help his business," Jordan Libowitz, communications director at Citizens for Responsibility and Ethics in Washington, a left-leaning public policy group, told the Associated Press.

Christopher Devine, an associate professor of political science at the University of Dayton, said Trump may have a business angle.

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However, he added that he believed Woods was deserving and calls his Masters victory "the greatest comeback in sports of all time."

"If President Obama or Hillary Clinton had given the award to Tiger, no one would have batted an eye," Prof Devine said.

Woods is the fourth professional golfer to receive the award. George W Bush presented the Medal of Freedom to Arnold Palmer and Jack Nicklaus and Mr Obama presented it to Charlie Sifford, sometimes referred to as the "Jackie Robinson of golf."