A federal appeals court has granted a stay of execution for Missouri inmate Russell Bucklew, hours before he was scheduled to die for killing a southeast Missouri man in 1996.

The 8th U.S. Circuit Court of Appeals on Tuesday cited concerns about Bucklew's rare medical condition, which raised the risk of "unnecessary pain and suffering by the inmate."

It wasn't immediately clear if the state would appeal to the U.S. Supreme Court.

Bucklew suffers from a rare condition that causes weakened and malformed veins.

It would have been the first execution in the nation following a botched lethal injection last month in Oklahoma.