Mark Strong has said the lessons learnt during the First World War are at risk of being forgotten.

The actor, 56, said people today have “absolutely no perception” of what it must have been like to fight during the conflict.

Speaking at the premiere of Sam Mendes’s war epic 1917 in London, he told the PA news agency: “It’s a fantastic film to understand what that generation went through.

The cast and crew of 1917 at its premiere in London
The cast and crew of 1917 at its premiere in London (Ian West/PA)

“We have absolutely no perception of what it must have been like to live during that time, to be conscripted and to have to go over and fight.”

Asked whether he thought lessons were at risk of being forgotten, he said: “As it drifts into the distant past more and more, yes. I think it needs people to keep telling the stories.”

Strong stars as a captain who helps two young soldiers (George MacKay and Dean-Charles Chapman) on their journey across enemy territory.

Royal Film Performance of ‘1917
The Prince of Wales shakes hands with Mark Strong at the premiere (Isabel Infantes/PA)

He said: “All the characters in it are stopping points in the journey of these boys.

“Colin Firth gives them a command and they are off to see Benedict Cumberbatch’s character at the end.

“On the way they meet a bunch of people and one of them is Captain Smith who meets them at a very important time and basically helps them along on their journey.

“I think he is one of the few individuals in their journey who is actually kind to them.”