Hong Kong action star Jackie Chan has broken his silence on his older appearance while celebrating his 70th birthday over the weekend.

The Rush Hour star sparked health concerns about a month ago when photos of him with grey hair and grey facial hair went viral on social media.

On Sunday (April 7), Chan marked his birthday milestone by sharing several throwback photos of himself on Instagram and reflecting on ageing.

“Even before today, many friends have been reminding me: ‘Jackie, it’s going to be your 70th birthday!’ Every time I hear this number, my heart would stop for a second – l’m 70 years old already?” he said.

The actor added: “After recovering from the shock, the second thing that would come to my mind is a saying that my big brother, Sammo Hung once said: ‘Being able to grow old is a fortunate thing.’

“Especially for us stunt people, we don’t know how lucky we are to be able to grow old.”

Chan also assured fans that he's in good health and clarified that his aged appearance was just for a character in an upcoming film.

“The character requires me to have white hair, white beard and look old,” he said.

“Over the years, I’ve always been willing to try new things for a movie, no matter if it’s a challenging stunt or a breakthrough appearance for a character.”

Reflecting on his 62-year career in the entertainment scene, Chan said he’s “lucky” to still be filming today.

Sharing some words on the throwback pictures uploaded on Instagram, the actor said: “Looking at these photos brings back so many fond memories. All I can say is: I love making movies and I love you all.”