The new 18-team format has replaced the former World Group, with Barcelona footballer Gerard Pique's Kosmos investment company pouring $3 billion into a 25-year deal with the 119-year-old tournament.

The nations have been split into six three-team groups, with the winners and two best runners-up to reach the quarter-finals.

Marin Cilic's Croatia, who beat previous winners France in last year's final, play the first match on Centre Court against a Russian outfit who came through qualifying.

The semi-finals will both be held on Saturday, November 23, with the final the following day.

The ITF said the four semi-finalists would automatically qualify for the 2020 finals, the worst two teams in the group stage will drop into the Zone Group competition, with the other 12 sides to play in the qualifiers.