Haggerty says”successful talks” have happened between the ATP and ITF after concerns were raised to a congested player schedule.
“In the heart of the problem is that the calendar,” Haggerty said.
“Can there be a way to work and collaborate together?”
An World Cup-style occasion has become an overhaul and replacing the Davis Cup format that is current to be held in Madrid.
The ATP occasion, involving 24 groups that are international, will function as a curtain-raiser for the men’s 2020 season just six weeks later.
“We’re responsible for making certain that the players have a flow during the entire year, so they may start and finish strong,” added Haggerty.
The ATP event has been backed by world number one Novak Djokovic, however he also said producing two”typical events” wouldn’t be good for the game.
France are now hosting Croatia in the closing of away Davis Cup and the last ever home.
The ITF consented to reform the Davis Cup in August, using a $3bn (£2,34m), 25-year partnership agreed with Kosmos, the investment group founded by Barcelona defender Gerard Pique.
Haggerty said:”We had very productive meetings in London with all the ATP, Kosmos, the ITF, the Grand Slams and the gamers to speak about what’s the best thing to do for Tennis.
“We’ll meet again in January to continue the dialogue.”