"I was offered something in excess of $US100 million ($A144 million) by the Saudis, to do the job probably similar to the one that Greg is doing," Nicklaus said in a story with Fire Pit Collective. "I turned it down. Once verbally, once in writing. I said, 'Guys, I have to stay with the PGA Tour. I helped start the PGA Tour.'"

Saudi Arabian organisers launched the new circuit and plan to hold the inaugural event at Centurion Club outside London from June 9-11. In addition, five tournaments will be played in the United States and a team matchplay finale at Trump Doral in Miami in October.

The PGA Tour denied requests from players, including Phil Mickelson, who asked to participate in the London tournament.

Players must request clearance to play in the second LIV event by Tuesday.

An unauthorised Mickelson biography written by Alan Shipnuck, being released this week detailing his alleged gambling losses and comments about the Tour and other golfers, is drawing media attention.

Already, comments about Saudi Arabian human rights allegations caused a firestorm for Mickelson and he did not play in the Masters. He last played in an event in January and withdrew from the PGA Championship this week despite being the defending champion.

"My advice to Phil? My advice to Phil would be to be patient," Nicklaus said in the story published on Monday. "The world is a very forgiving place. But he's the one – he has to decide where he wants to play and what he wants to do."