Andy Murray and Novak Djokovic are among the stars to have reacted positively to the creation of an annual season-ending event, starting in 2019, that will have a total purse of $20 million.

"We think the change we are making will make it so much more appealing and tangible to the top players," David Haggerty, president of the International Tennis Federation, told The Associated Press on Monday.

Established in 1900, the Davis Cup has struggled for relevance at times in a crowded sporting calendar in recent years because many top players have chosen not to play.

In this revamp, the World Cup of Tennis would be played over seven days in the traditional week of the Davis Cup final, rather than across four weekends in February, July, September, and November. It would comprise a round-robin format followed by a quarterfinal knockout stage. Each tie would be best-of-three sets and consist of two singles and a doubles.

Sixteen teams would automatically qualify for the finals, and two more would be selected.

"In November 2018, players will know who is playing in November 2019 and they'll be able to factor that into their plans, travel, and prioritize it," Haggerty said in a phone interview. "Now, you may know where your first tie is, but you're not sure where your second would be. You're not sure of the surface.

"There are some uncertainties and this will bring some clarity to it to help make the commitment to play."

The event has been devised in conjunction with investment group Kosmos, which was founded by Barcelona and Spain soccer player Gerard Pique. The partnership is worth $3 billion over 25 years.

Pique has been a big driver behind the overhaul. He personally presented the proposal to the ITF board in Barcelona on Saturday, a few hours before playing that night for his team in the Spanish league.

"He has had conversations with players, and the players council," Haggerty said of Pique. "The players are very supportive of this idea.

"I have to say that I haven't spoken to them directly, but I know that Gerard has had some conversations over the last few days and had positive comments from Andy Murray, from Novak Djokovic."

The ITF board unanimously endorsed the proposal, which will be submitted at the ITF's annual general meeting in Florida in August.

Haggerty said a decision on the venue for the inaugural competition will be taken in four to six weeks. There has been interest in the United States and Asia, among others.

It will be on a hard court to begin with, so players featuring in the ATP Finals in November don't have to change surfaces.

"We want to find a relevant city that is world-class," Haggerty said, "where sport and entertainment can come together, where fans will travel.''

Haggerty said the ITF's long-term goal is to turn the Fed Cup into a similar one-week event.

"This is a complete game-changer for the ITF and for tennis," he said.