“I look forward to coming back when it is finished, if not before,” said the 82-year-old star.
“I think it is going to take six years and I plan to be around.”
Once finished, the 807ft (246m) tower – featuring a swimming pool, a spa, a gym and a garden – will be the UK’s tallest building outside London.
De Niro said: “I haven’t seen the city yet but I’d like to come back. Everyone is very nice, we’re having a very nice time.
“It’s great being here in Manchester because it has real character, we’re proud to be part of it.”
The skyscraper has been designed by architect Ian Simpson.
Salboy was created by the Salford bookmaker Fred Done.