World number two Alcaraz, 19, and Badosa, 22nd in the WTA rankings, will face five other teams in the July 19-23 event in France.

Richard Gasquet, part of the winning team in 2017, unites with 2013 winner Alize Cornet for the hosts, with Switzerland represented by Olympic champion Belinda Bencic and Leandro Riedi.

Event organiser Iva Majoli told a Tuesday press conference the three other teams would be announced "in the coming weeks".

Teams are split into two groups of three on the clay courts at Nice with rubbers consisting of two singles and a mixed doubles.

First staged in 1989 it moves to the French riviera from its former traditional home in Perth, Australia.

The USA hold the most titles with six, while the Swiss were the winners of the last edition four years ago.

The competition is named in honour of Harry Hopman, the late Australian tennis player and coach who helped guide his country to 15 Davis Cup titles between 1938 and 1969.