Republican Gov. Sam Brownback says he wishes Kansas had preserved part of an income tax break he championed as a boon for small businesses.

Brownback cited the death of the exemption for more than 330,000 farmers and business owners as one of his regrets during his 6½ years as governor. He reflected on his tenure during a Statehouse news conference following his nomination by President Donald Trump to serve as U.S. ambassador-at-large for international religious freedom.

His departure would elevate Lt. Gov. Jeff Colyer, a fellow GOP conservative, to governor. Brownback said he doesn’t know whether he’ll wait until his ambassador’s appointment is confirmed by the U.S. Senate before resigning as governor.