George Clooney's World War II drama "The Monuments Men" will not arrive in theaters this year as planned because the film's visual effects could not be completed in time, the actor and director said. The tale of a ragtag band of art historians, museum curators and academics racing to rescue paintings and sculptures looted by the Nazis slated to open Dec. 18 now will be released by Sony Pictures early next year. "We just didn't have enough time," Clooney said Tuesday by phone from London, where he and producing partner Grant Heslov were to start a 16-hour scoring session with composer Alexandre Desplat and a 110-piece orchestra as part of their race to complete the film. "If any of the effects looked cheesy, the whole movie would look cheesy," said Clooney, who directed the film and stars in it. "We simply don't have enough people to work enough hours to finish it." By moving into 2014, "Monuments Men" will be ineligible for the upcoming Academy Awards. But Clooney said Oscar attention was never his goal for the film, which he and Heslov adapted from Robert Edsel's nonfiction book "The Monuments Men: Allied Heroes, Nazi Thieves, and the Greatest Treasure Hunt in History." "All we've ever said, from the very beginning, is that we wanted to make a commercial, non-cynical piece of entertainment," Clooney said. He said the intention was to make an ensemble film in the style of "The Guns of Navarone." In addition to Clooney, the film stars Matt Damon, Bill Murray, Jean Dujardin, John Goodman and Cate Blanchett. It was filmed in Germany and England earlier this year. After arriving in London a day ago, Clooney said he and Heslov realized they were facing an impossible pursuit. "I looked at Grant and said, 'We're dying,'" Clooney said.