April 21 (Reuters) - Minneapolis Federal Reserve Bank President Neel Kashkari said Friday that immigration has been a key driver of U.S. economic growth, and without it, or increased fertility domestically, the economy simply will not grow as fast as before.

"We can either accept slower growth, we can subsidize fertility, which is pretty expensive, right, or you can embrace immigration," Kashkari said at Hamline University in St. Paul, Minnesota. "And those are the three choices, and that's literally math, and you can pick which one you like."

Kashkari said he had not yet factored in any of the Trump administration's plans for tax, regulatory or other fiscal reforms into his forecasts, saying it was still too early to know what policies will be implemented.

(Reporting by Ann Saphir; Editing by Meredith Mazzilli)