American golfer Kevin Na has resigned from the PGA Tour so he can play in a Saudi-backed LIV Golf Invitational Series event without the threat of punishment.

Na, ranked 33rd in the world, is one of many golfers listed in the field for the June 9-11 event at Centurion Club outside London, including former world number one Dustin Johnson and former Masters champion Sergio Garcia.

The PGA Tour on Wednesday had reiterated a warning to members, saying those who featured on the Saudi-funded breakaway circuit would be "subject to disciplinary action".

Na, who has won five PGA Tour titles in his career, said on Saturday he appreciated the tour for the opportunities it had provided over 19 years but "recent developments in the professional golf world" had forced him to reconsider his options.

"If I exercise my right to choose where and when I play golf, then I cannot remain a PGA Tour player without facing disciplinary proceedings and legal action from the PGA Tour.

"I am sad to share that I have chosen to resign from the PGA Tour. This has not been an easy decision and not one I take lightly.

"I hope the current policies changes and I'll be able to play on the PGA Tour again."

Na described the new tour as an "exciting new product" and said he hoped fans would "enjoy the buzz it brings to golf".

"I am thrilled to begin the next chapter in my career, starting next week at the inaugural LIV Invitational series event in London. I hope you'll continue to support me," he said.

Both the PGA Tour and DP World Tour had declined all requests from members who had asked for releases to compete in the rival series.

The event at Centurion has $US25 million ($34.69 million) up for grabs,- including $US4 million for the winner.

Reuters / ABC