PIERRE, S.D. — South Dakota’s governor vetoed a bill that would have made the state the first in the U.S. to approve a law requiring transgender students to use bathrooms and locker rooms that match their sex at birth.

Republican Gov. Dennis Daugaard, who initially reacted positively to the proposal but said he needed to research the issue, rejected the bill Tuesday after groups such as the American Civil Liberties Union and the Human Rights Campaign insisted it was discriminatory.

In his veto message, Daugaard said the bill “does not address any pressing issue” and that such decisions were best left to local school officials. He also noted that signing the bill could create costly liability issues for schools and the state. The ACLU had promised to encourage legal action if the bill became law.

“I am so happy right now. You have no idea,” said 18-year-old Thomas Lewis, a transgender high school student in Sioux Falls. Lewis said he has support at his school, but that the veto shows such support goes beyond his friends.