In the mid-late 90s, the Honda plant in North Carolina was making 3 rear-engine riding models, and then 1/2 dozen front engine lawn tractors. The last riding equipment model Honda offered in the USA was build by John Deere (it was built with an 18 or 20 hp Honda engine). Honda left the riding equipment market in 2000, and decided to focus on their core engine and 21" walk-behind mower business. Honda no doubt considered the ZTR market, but no products were ever introduced. Larger Honda V-twin engines are used by many current ZTR manufacturers.
Honda Europe / Honda U.K. stills offers a few rear-engine riders and front-engine lawn tractors, which are made in Italy.