Depp and Heard starred together in "The Rum Diary," filmed in Puerto Rico in 2009.
In 2012, Depp split with his partner of 14 years, French model-singer Vanessa Paradis. They have two children.
In a trademark off-the-wall comment, Depp said: "I think that I would be better at making women's shoes than I would be at wedding planning, I can't plan anything. I'm really bad at that stuff."
The 50-year-old actor was in Beijing to promote his new movie "Transcendence." Depp plays a terminally ill scientist who downloads his mind into a computer in the sci-fi drama that asks: What if we could upload a human mind into a computer? It also stars Rebecca Hall as Depp's wife and Morgan Freeman.
"The technology that exists within the film, what I find most fascinating is that a lot of it exists already and by all accounts from scholars and professors and scientists that species of technology is not far away, that kind of artificial intelligence," said Depp in an interview.
"It's one of those films that one person is forced to make a choice in an instant, when your loved one is dying and you have a split-second decision if you have the ability to upload their consciousness into a computer, would you do that? It's quite a strange decision to make but for love I think we would all do it."
"Transcendence" comes out in China on April 18 — the same day as the U.S. release. China is the only country currently where "Transcendence" will be showing in 3-D — a format popular with Chinese audiences.
China is also the only international stop Depp is making as part of the movie's promotion tour, illustrating the growing attention Hollywood is paying to the country that now has the world's second-biggest box office after the United States.
Last Monday, Chris Evans, Scarlett Johansson and Samuel L. Jackson promoted "Captain America: The Winter Soldier" in Beijing, followed the next day by "The Amazing Spider-Man 2" stars Andrew Garfield, Emma Stone and Jamie Foxx.
"With regard to Hollywood, China is quite a large market, certainly," said Depp, who was on his first visit to China. "I think there will be a lot more films coming here, a lot more people coming here and continuing the trend."