Jon Hamm is ''amazed'' it's taken more than 25 years for 'Beirut' to reach cinema screens.

The 46-year-old actor - who stars as a former US diplomat during the Lebanese Civil War in the 80s - has admitted to being shock that it's taken so long for Tony Gilroy's script - which was penned in the early 90s - to come to fruition.

Asked what attracted him to the new espionage film, Jon said: ''I was amazed that no one had made this movie. It's a wonderful story ... the length of time between when it was written and now has only made it more poignant in a way, and resonate in a way. We're still dealing with the same stuff.''

Jon - who is best known for playing Don Draper in the hit TV series ' Mad Men' - revealed he embraced his character because of his ''human'' approach to diplomacy.

And the Hollywood star appreciated that the script didn't hit viewers ''over the head'' with its message.

Speakin to Collider, Jon explained: ''What I liked about it, other than the guys attached to it, was that it's an opportunity to play a character who has everybody's best interests at heart.

''It's like, 'Let's move forward. If we're going to sit here and bump heads, we're just going nowhere. Get people into a room, deal with them on a human level and try to move forward.'

''It's incredibly deftly told - it's not hitting you over the head.''