I found some additional articles on what he said about this, and he did indeed flat out say he expects the "other countries" to pay the tariffs. For instance, this.

A sweeping tariff policy will kill two birds with one stone, Trump says: It could find a new source of revenue for the U.S. government, which could offset losses from lowering or eliminating certain forms of income tax, while extracting money from rival governments.

That's not how tariffs have worked at any point in history.