PICKENS, S.C. -- Pickens County Sheriff Rick Clark says he won't lower the flag outside the sheriff's office to half-staff to honor Nelson Mandela because the South African civil rights leader was not a United States citizen.

Clark made the announcement Friday on his Facebook page, writing "Nelson Mandela did great things for his country and was a brave man but he was not an AMERICAN!!!"

Clark said the sheriff's office American flag was at half-staff Friday to honor a Florence County deputy killed in a wreck and Saturday for Pearl Harbor Day, but will fly at full staff on Sunday and Monday.

Mandela was imprisoned for nearly 30 years while trying to bring racial equality to South Africa, then became the country's president and a civil rights leader. He died Thursday. President Barack Obama ordered flags in the United States flown at half-staff in honor of Mandela through sunset Monday.

Clark pointed out Obama's order was a proclamation and does not have the force of law. He said he would have made the same decision if he was in office in 2005, when President George W. Bush ordered flags flown at half-staff after the death of Pope John Paul II.

Clark became sheriff this year.

Pickens County officials said while Clark is free to do what he wants to do with the flag outside the sheriff's office, American flags at other county offices will remain at half-staff to honor Mandela.