Craig, who is now 51 years old, was thought to have finished as Bond after saying he would rather “slash his wrists” than play the secret agent again while on the 2015 press tour for Spectre.
He later walked back those comments and, after being offered a reported £18.4 million to appear in the sequel, finally agreed to return as 007.
Harris, who plays Bond’s colleague and on-off love interest Miss Moneypenny, will reprise her role in Bond 25, which is due for release in spring 2020.
And though the forthcoming film was expected to be Craig’s last, Harris hints that the Chester-born actor might not be done yet.
“Well the thing is that everyone is assuming this is his last film,” she told The Independent at Saturday’s Formula E E-Prix in Monaco.
“Daniel has never said that, so we don’t know. It’s still open, who knows.
“Genuinely I think he doesn’t know. Nobody does. It depends on this film and if people turn out and are like ‘We want Daniel’ – which I think they will – then he may well be back for another one.”
Asked who she thought would be a good replacement for Craig when he does eventually elect to hang up his Walther PPK, Harris said she simply hopes that Craig will stay on.
“I started with Daniel so all I’ve ever known is Daniel. I know he’s amazing to work with, I love working opposite him, so I want him. I can’t really think of anyone else.”
The next Bond film has had a difficult production. Danny Boyle was initially set to co-write and direct the film but parted ways with the producers following creative differences.
Cary Joji Fukunaga has since taken over as director, with the film now going by the working title Eclipse. Reports previously claimed that Bond 25 had the working title Shatterhand, which was used in the books as an alias for arch-villain Ernst Stavro Blofeld.