Kids got the chance to join in with the celebration as the 25-day countdown to the FIFA Women's World Cup begins ©FIFA

More than 4,000 football fans crossed the Sydney Harbour Bridge to celebrate the 25-day countdown to the FIFA Women's World Cup, due to be jointly staged by Australia and New Zealand.

American soccer star Joy Fawcett, New South Wales (NSW) Minister for Jobs and Tourism John Graham and representatives from governing bodies Football Australia, New Zealand Football and FIFA were among those to join in with the celebrations.

Fans got the opportunity to carry the flags of all 32 nations that are set to participate in the FIFA Women’s World Cup as well as view live cultural performances and presentations.

A 17-metre-long 'unity' jersey was also unveiled on the Sydney Harbour Bridge that aimed to reflect the colours of the landscapes of co-hosts Australia and New Zealand.

This year's Women’s World Cup is due to be staged across nine cities in the two countries from July 20 to August 20.

Sydney is poised to host the tournament opener between Australia and the Republic of Ireland, while Stadium Australia has also been chosen to stage the Women’s World Cup final.

"Today we stand on one of Australia’s iconic structures, excited to host the world’s best players and their passionate football fans in NSW," said Graham.

"I am excited to have 11 matches scheduled here in NSW and welcoming all the world class football teams and their fans at what is set to be the biggest FIFA Women's World Cup ever.

"This tournament has the potential to be one of the biggest sporting events in Sydney since the 2000 Olympics and the NSW Government is happy to support the FIFA Women’s World Cup 2023."

Football Australia chief executive James Johnson said it was a "fitting way" to celebrate exactly three years to the day when the country secured the hosting rights along with New Zealand.

"Today, the Sydney Harbour bridge was closed to celebrate football," said Johnson.

"This is a significant moment for our game and is something which the Australian football community should take pride in and savour - this is our time."

This year’s Women’s World Cup will be the first to feature 32 countries after increasing from 24.

Haiti, Morocco, Panama, the Philippines, Portugal, Ireland, Vietnam and Zambia are all set to make their first appearances in the tournament.

"I think we can expect to have good quality football," Rhiannon Martin, head of FIFA Women’s World Cup, told Australian broadcaster ABC.

"We saw in the Confederations qualifiers last summer, how the level has improved over the last couple of years.

"It's an inspiration for every player to have got to here.

"Hopefully like in the men's World Cup in Qatar [in 2022], some of the teams performing for the first time will go better than they were.

"We saw what happened with Morocco and Saudi Arabia in the men's World Cup.

"We hope to have some surprise results.

"All of the groups are very strong.

"I know Australia have got a strong group.

"We're looking forward to fantastic football in 25 days."