The 30-year-old opted out of the final year of his contract with the Knicks in order to test free agency, and has been linked with a number of teams, but has not ruled out returning to Madison Square Garden.
Jackson told The AP: "I expected [a decision] yesterday and the day before yesterday. But no, we're waiting.
"I felt really good about my conversation with Carmelo. We really struck a chord. The two of us, I think feel really passionately about what we're trying to get accomplished. It's his ability to stay, be patient, lead and watch us develop a winner.
"He knows what he has here and what is possible and I think he'd like to play with Carmelo and I think he'd like to play for a winner. And we can't guarantee that but with him, we'd guarantee a much better chance."
The Knicks have reportedly offered Anthony a maximum contract worth almost $130m (£76m) over five years.