ATP Cup organisers have apologised to Moldova after the wrong national anthem was played before their opening match in the new team tournament.

The Romanian national anthem was instead played before their match against Belgium in Sydney on Friday.

"At the start of the Moldova v Belgium match we mistakenly played the wrong national anthem for Moldova," the ATP said.

"We are sincerely sorry and have apologised personally to Team Moldova."

Moldova was one of the last countries to qualify for the inaugural team event being played in Sydney, Brisbane and Perth.

The European nation is being led by world number 46 Radu Albot, who became his country's first ATP Tour title winner when he beat Britain's Dan Evans at last year's Delray Beach Open in Florida.

Moldova have been drawn in the same group as Britain, who are without the injured Andy Murray, as well as Belgium and Bulgaria.

The ATP Cup sees 24 nations split into six groups across the three Australian cities, with eight teams qualifying from the round-robin stage to compete in a knockout phase in Sydney.

The start of the tournament has been overshadowed by the widespread bushfires which have affected Australia.