The Serbian men’s team stormed to gold in Rio de Janeiro five years ago, beating rivals Croatia 11-7 in the final.

The result crowned a dominant period for the nation, with the team having entered the Games as the reigning world and European champions, as well as having World Cup and World League titles to their name.

Serbia’s status has been challenged since Italy were crowned world champions in 2019, while Hungary claimed the European title last year.

Spain finished as the silver medallists in both competitions.

The four teams will be among seven European nations featuring in the 12-team men’s competition, alongside Croatia, Greece and Montenegro.

European nations have won 26 of the 27 men’s Olympic water polo titles, with the United States providing the only exception when they triumphed in St. Louis in 1904.

Serbian captain Filip Filipović, the most valuable player at Rio 2016, believes his team are ready for the challenge of defending their title.

"We're finally in Tokyo after a year of waiting," Filipović said.

"Thanks to the Olympic Committee of Serbia, the preparations for coming to the Games and staying in the Olympic Village are ideal and we have all the conditions for a good result.

"My teammates and I will show in the pool that we are ready for everything that awaits us."

The defending champions will face Australia, Croatia, Kazakhstan, Montenegro and Spain in Group B, with their campaign beginning on Sunday (July 25).

World champions Italy head Group A with their opponents including hosts Japan, Greece, Hungary, South Africa and the United States.

The top four nations in each group will advance to the quarter-finals of the competition.

The US women’s team will be seeking a third Olympic title, with their two triumphs having come at London 2012 and Rio 2016.

Margaret Steffens and Melissa Seidemann could become the first women’s water polo players to win three consecutive titles having been a member of the two successful squads.

The reigning world champions will face hosts Japan in their opening match tomorrow, with the Russian Olympic Committee, China and Hungary completing the Group B line-up.

European champions Spain feature in Group A, alongside Australia, Canada, the Netherlands and South Africa.

Only one team in each five-nation group will fail to make the quarter-final stage of the competition.

The women’s competition concludes on August 7, with the men’s ending the following day.