The PGA Tour and DP World Tour have announced a 13-year joint venture partnership amid the ongoing threat posed by the Saudi Arabia-backed LIV Golf Invitational Series that has already poached a handful of high-profile golfers.

As part of the new partnership, which runs through to 2035, the PGA Tour will increase its existing stake in European Tour Productions to 40% from 15%.

In addition, from 2023, the top 10 players in the DP World Tour's rankings will receive PGA Tour cards for the following season. The DP World Tour will also guarantee growth in annual prize funds to its membership for the next five years.

"The game of golf is rallying," PGA Tour Commissioner Jay Monahan said during a video news conference with DP World Tour Chief Executive Officer Keith Pelley.

"Today's announcement should serve as further evidence that the ecosystem of professional golf continues to innovate and thrive."

While no additional co-sanctioned events were announced as part of the pact, which builds on the success of the existing strategic alliance between the two Tours that was unveiled in November 2020, the circuits said they would continue to coordinate a worldwide schedule.

"It is a natural extension and progression of what we have been doing over the past few years and I passionately believe that this move is the right thing for our players, our Tour, our fans, and the game of golf in general," said Pelley.

The announcement by the US and European circuits was made just as the opening news conference at LIV Golf's first US-based event was getting underway at Pumpkin Ridge Golf Club in Portland, Oregon.

Among those who have joined LIV, where each person in a 48-player, no-cut event is guaranteed a payday, are World Golf Hall of Famer Phil Mickelson and fellow major winners Dustin Johnson, Bryson DeChambeau, Brooks Koepka and Sergio Garcia.

LIV Golf is bankrolled by Saudi Arabia's Public Investment Fund and has lured several recognisable names with a $255 million purse spread over eight events this year.

The 48-player field in Portland this week includes nine of the last 21 major winners, four former world number one players and nearly half of its competitors are currently ranked in the top 100.

The PGA Tour, in a decision released moments after play in the lucrative breakaway series began outside London three weeks ago, suspended members who played the LIV event and said anyone else who makes the jump will face the same fate.

The DP World Tour has also suspended members who played the LIV event from three upcoming tournaments and fined them £100,000 each. The circuit also said participation in a further conflicting tournament without the required release may incur further sanctions.