Britain's Prince Harry was in the German city of Düsseldorf on Saturday to open the 2023 Invictus Games for combat veterans.

More than 500 competitors from 21 countries are taking part in the contest, which gets underway as Germany swelters under temperatures of over 30 degrees Celsius (86 degrees Fahrenheit).

Harry told the 20,000-strong audience inside Düsseldorf's Merkur Spiel-Arena that the games were about showcasing respect and appreciation.

"Look at your uniform," he said. "This may no longer be a camouflage suit, but you again have a flag on your shoulder or your chest. You and your families — you're part of a team again." 

The son of King Charles III was accompanied by German Defense Minister Boris Pistorius at the opening ceremony as the national teams filed into the arena. There are 38 men and women representing Germany this year. 

Pistorius told the crowd that the athletes in the competition were impressive role models. "You are proof that there is always a way forward," he said.

He also called on continued support for Ukraine to fend of Russia's invasion, saying backing was needed "as long as it takes." 

Chancellor Olaf Scholz, who is attending the G20 summit in New Delhi, sent a video message, while US rapper Macklemore put on a concert.

What are the Invictus Games?

The sports event was created for war veterans who have been injured in battle and has been taking place roughly every two years since 2014. It's the first time it's being hosted by Germany.

According to the Invictus Games website, the goal of the event is to "give soldiers who are wounded, injured or ill in body and soul a greater awareness and recognition in society and to support their path to rehabilitation."

More than half of the 500 veterans competing suffer from the psychological effects of battle, such as post-traumatic stress disorder, the website adds.

Earlier in the day, Harry was welcomed by German Defense Minister Boris Pistorius and Düsseldorf Mayor Stephan Keller at the town hall, where he signed the city's Golden Book.

Meanwhile, a small group of anti-war protesters gathered nearby under the motto: "Don't advertise killing," holding various placards in German and English.

Competitive events in the Invictus Games, which includes events in 10 disciplines, begin on Sunday and wrap up on September 16. Prince Harry was expected to remain in Germany until the competition's conclusion.

Harry himself served a 20-week tour spanning 2012 and 2013 in Afghanistan as an Apache helicopter copilot gunner. He launched the first Invictus Games in London in 2014.

nm/msh (AFP, AP, dpa)