Iron Man star Robert Downey Jr has visited Great Ormond Street Hospital, where he met young fans on the cancer ward.

Ahead of the European premiere of Captain America: Civil War in London on Tuesday, the film's star spent Monday afternoon visiting patients and their families and handing out Captain America goodies to his young fans.

Seven-year-old Ethan Miller, who suffers from the rare blood disease ITP as well as type 1 diabetes, was 'over the moon' to meet the Hollywood actor.

Scroll down for video

Dream come true: Iron Man star Robert Downey Jr has visited Great Ormond Street Hospital, where he met young fans on the cancer ward

His father Lee explained: 'Ethan has been in and out of hospital a lot in the past three years. He watches the films all the time and virtually lives in his Iron Man costume.

'Ethan was over the moon to meet his hero and it has really helped to lift his spirits.'

The pair posed together in the hospital chapel, with Ethan wearing his Iron Man costume and pulling the signature Iron Man pose alongside the Hollywood star.

Good deed: Ahead of the European premiere of Captain America: Civil War in London on Tuesday, the film's star spent Monday visiting patients and their families - pictured with Chloe Bowers, aged 5 from Ruislip

Say cheese: Rober was seen handing out Captain America goodies to his young fans - picturerd meeting young fan Michael, aged 7 from Edmonton

Downey has played Tony Stark - otherwise known as Iron Man - since 2008 and is known for using his fame and acting skills to surprise young fans.

In 2015, he visited Alex Pring, who was born with a partially developed right arm, dressed up in character as Tony Stark and he presented Alex with a bionic Iron Man arm.

He also had a special message for a young boy suffering from cystic fibrosis, donning a Tigger costume and posing for an Instagram photograph to cheer him up and invite him to the Captain America premiere.

What a hero: Downey has played Tony Stark - otherwise known as Iron Man - since 2008 (pictured with Denisa Kapsalis, aged 7 from London)

Great guy: The actor is known for using his fame and acting skills to surprise young fans - seen holding Charlie Dawson, one, from Southend-on-Sea, Essex

Great Ormond Street Hospital is one of the world's leading children's units, treating young patients with rare, complex and life-threatening conditions.

The visit was organised by Disney officials, who have worked with the hospital's charity since 2008, raising more than £10 million for the unit's redevelopment.

Other famous faces that have paid a visit to the children's charity include actor Johnny Deep, footballer David Beckham, Formula One ace Lewis Hamilton, singer Nicole Scherzinger and Hollywood actor Dwayne 'The Rock' Johnson.