Well, he could be referring to something like the westminster system (used in the UK and adopted in places like Canada.)
Frankly, I think Trump would be even more dangerous under the westminster system. Under the US system, he does have to contend with congress to at least some degree. (Granted the GOP is largely acting like trained seals to applaud everything Trump does, but in theory they could grow a spine and oppose him.) But if Trump were head of government in the westminster system, not only would he have executive power, but he would also have control over the legislature.