Mickelson expresses 'deepest sympathy' for families of 9/11 victims amid LIV criticism

Phil Mickelson has expressed his "deepest of sympathy and empathy" for the families of the 9/11 victims amid continued criticism over his decision to join the LIV Golf Invitational Series.

The controversial eight-event Saudi-backed breakaway circuit, which got under way in London last week, has a prize fund of $250million that is bankrolled by Saudi Arabia's Public Investment Fund (PIF).

Mickelson and the other American players taking part in the series have been accused by a group representing victims' families and survivors of "sportswashing" – the practice of using sport to improve a tarnished reputation.

Terry Strada, the chair of the 9/11 Families United, said in a statement: "Whether it was the appeal of millions of dollars of hard cash, or just the opportunity to prosecute your professional grievances with the PGA, you have sold us out.

"This is a betrayal not only of us, but of all your countrymen."

Strada cited Saudi Arabia's prominent role in the terror attack 21 years ago, with Osama bin Laden and 15 of the 19 hijackers being Saudi nationals.

In another uncomfortable news conference on Monday ahead of this week's U.S. Open in Massachusetts, Mickelson was asked directly about Strada's comments.

"I would say to the Strada family, I would say to everyone that has lost loved ones, lost friends on 9/11 that I have deep, deep empathy for them. I can't emphasise that enough," he said.

"I have the deepest of sympathy and empathy for them."

Asked if he intended to respond privately to the letter, Mickelson repeated his earlier answer.

Mickelson and the others to have joined up for the series have also faced criticism from their colleagues, with Rory McIlroy – the winner of last week's Canadian Open – among the more vocal of those to speak out against the LIV Series.

"I certainly respect Rory," Mickelson said. "I thought what a great finish on Sunday and a great accomplishment. What a career he has had. I certainly respect him. I respect his ideas. I respect all the players that choose to stay on the PGA Tour.

"I certainly think extremely highly of many of the players on the PGA Tour and their right to their own decisions.

"I gave as much back to the PGA Tour and the game of golf that I could throughout my 30 years here, and through my accomplishments on the course I've earned a lifetime membership. I intend to keep that and then choose going forward which events to play and not."