London, Aug 14 (IANS/EFE): British director Guy Ritchie's "The Man from U.N.C.L.E.", which opens this week, pays tribute to the 1960s, with two secret agents, one from the CIA and the other from the KGB, setting aside their differences to work together.

Ritchie, who is a fan of spy films, especially the early James Bond movies, said in an interview with EFE on Thursday that the greatest challenge was maintaining the original style of the classic television series but adapting it to a contemporary audience.

In the film, which takes place in the era of confrontation between the then Soviet Union and the US, CIA officer Napoleon Solo (Henry Cavill) and KGB agent Illya Kuryakin (Armie Hammer) have to join forces to stop a gang out to develop nuclear weapons.

"We are particularly attracted to the 60s spy world. There is something about that period which we feel is the golden age of the genre. I think it has a lot to do with the Cold War, that the US and Russia were so close to going to war, that there was a great worry that the world would destroy itself with nuclear weapons," Lionel Wigram, Ritchie's co-screenwriter, said.

Cavill and Hammer said that the principal reason that made them decide to participate in this project was the chance to work with Ritchie, who they admire for "Snatch" (2000) and "Rock N Rolla" (2008).

The stars described Ritchie as "relaxed, meticulous and flexible" in doing his job.