Tom Cruise broke off from promoting his latest film today to propose to his girlfriend Katie Holmes at the top of the Eiffel Tower.

The actor confirmed the engagement at a Paris press conference, where the 26-year-old actress - 16 years younger than her husband-to-be - sat in the second row, wearing a large diamond ring.

"Yes, I proposed to her... it was early this morning at the Eiffel Tower, so I haven’t slept at all," said Cruise, the start of Top Gun and the Mission Impossible series. "Today is a magnificent day for me, I’m engaged to a magnificent woman."

Asked why he chose the landmark, he said: "I’ve never been to the Eiffel Tower. It’s Paris, it’s a beautiful city, it’s very romantic."

Cruise said no date has yet been set for what will be his third wedding: "We haven’t discussed that -- one step at a time," he said. "Let’s see. We’re not sure."

Holmes did not say anything at the press conference, but blushed and smiled. Dakota Fanning, the young actress and co-star of the Steven Spielberg-directed War of the Worlds, the film Cruise is currrently promoting, said: "I wish them the happiest marriage that anyone has ever had."

After the press conference, Cruise and Holmes took a train to Marseille for a special French premiere of War of the Worlds. Cruise was welcomed as an honorary citizen of the city by the Mayor Jean-Claude Gaudin.

Holmes was in London last week promoting her appearance in the upcoming Batman Begins. Holmes achieved fame in the American television series, Dawson's Creek, before attracting critical acclaim in the film, Pieces of April.

The couple announced their relationship in April, after Cruise broke up with Spanish actress Penelope Cruz and Holmes and actor Chris Klein called off their long-standing engagement. Recently, Holmes said that she was exploring Scientology, a religion that Cruise follows.

Holmes will become Cruise's third wife. His two previous marriages, to actresses Mimi Rogers and Nicole Kidman, have ended in divorce.

Today's announcement may end speculation in American tabloid newspapers and magazines that the Cruise-Holmes relationship has been a publicity stunt.

And the wedding will be a dream come true for the actress who told a magazine last October - before she even met Cruise - that when she was a little girl, "I used to think I was going to marry Tom Cruise". She also used to keep a poster of Cruise on her bedroom wall.