Missouri Governor Jay Nixon on Wednesday vetoed a bill requiring women to wait three days for an abortion, even in cases of rape or incest.
The state's Senate and House of Representatives in May approved the bill that would have extended the minimum waiting period before a woman could have an abortion to 72 hours from 24 hours, without exception.
Nixon, a Democrat, said in a statement that lawmakers' failure to include an exception for rape or incest "demonstrates a callous disregard for women who find themselves in horrific circumstances."
Republican Representatives Kevin Elmer and Andrew Koenig who sponsored the bill could not be reached immediately for comment.
The 24-hour waiting period remains in effect unless lawmakers vote to override Nixon's veto. A two-thirds' vote in both Republican-led chambers is required to override a veto in Missouri.
The bill passed the House by a vote of 111-39 and the Senate with a 22-9 vote, close to the two-thirds needed for a veto override.
If the veto is overridden, Missouri would join Utah and South Dakota as the only states to require women to wait 72 hours to have an abortion after an initial visit to a doctor, according to the Guttmacher Institute, a non-profit research organization that supports the right to abortion.
Utah's law does not require a 72-hour waiting period for victims of rape or incest and does not require a wait if a girl is aged 14 or younger, Guttmacher said.
(Reporting by Brendan O'Brien in Milwaukee; Editing by Peter Cooney)