I saw a video interview when he was on Air Force One where he was asked by a reporter if he paid Stormy Daniels her to keep her quiet, and he flatly denied he did. Here’s the video. The question comes at about 20 seconds in. That’s not what you’re asking, but it’s close.
Trump also made the following post on Truth Social in January of 2023. Stormy Daniels later took it as an admission by Donald that they, indeed, had a sexual encounter.
So, the literal reading is that “it” happened over seven years prior to either now - so “long past” prior to 2016, or over even seven years prior to the 2016 payment, so 2009. Either way, the “it” isn’t the payment. Trump loves to add as many copies of the word “very” as he can manage into any statement. So we might discount that as just hyperbole. But the statement is pretty hard to parse as anything but an admission. YMMV.
And quite why he is mentioning the Statute of Limitations is just pain weird. As if it is some sort of get out of jail card for past actions.