The Vatican's semi-official newspaper has called blockbuster film Avatar a sappy movie while criticizing its approach to the theme of man versus nature.

In L'Osservatore Romano, the Vatican said Avatar had inspiring special effects but noted the film's director, James Cameron, tells the story without going deeply into it while letting the film fall into sappiness, the Associated Press reported.

Avatar - which this week became the second highest grossing movie of all time - clearly outlines a message about protecting the environment, the Vatican says. However it also notes that the film gets bogged down by a spiritualism linked to the worship of nature.

Pope Benedict XVI, the Vatican's representative, has often talked about the need to protect the environment but he has expressed his views on the dangers of turning nature into a divinity.

Avatar was released on December 18 and to date it has grossed $1.34 billion at theaters worldwide. The movie has been generally praised for its special effects and is expected to be a competitive candidate for the Academy Awards.