As South Carolina approaches the one-year anniversary of a racially motivate massacre at a Charleston church, Gov. Nikki Haley (R) said Thursday that her party's likely presidential nominee, Donald Trump, needs to change his divisive rhetoric.

"I know what that rhetoric can do," Haley told the Associated Press on Thursday. "I saw it happen."

On a Wednesday evening last June, 21-year-old Dylann Roof attended a prayer service at the Emanuel African Methodist Episcopal Church in downtown Charleston. Police say he opened fire, gunning down nine churchgoers. Roof later claimed he was trying to start a race war. He has been charged with more than 30 federal counts, including committing a hate crime.

Roof had proudly celebrated the Confederacy, according to his online postings, and the shooting quickly sparked a national discussion about the Confederate flag, which at that time was still flying on the grounds of the South Carolina state capitol. Soon after the shooting, the state legislature voted to remove the flag.

Haley said in the interview Thursday that Trump's supporters are not racist or hateful.

"That's a different kind of anger," she told the AP. "They're upset with Washington, D.C. They're upset nothing's got done."

But Haley said Trump has a responsibility to use a civil, respectful tone, the AP reported.

"The way he communicates that, I wish were different," Haley said.

Ahead of the South Carolina Republican primary in February, Haley endorsed Sen. Marco Rubio (R-Fla.) instead of Trump, and she has repeatedly questioned the way that Trump describes immigrants and minorities.

In delivering a rebuttal to President Obama's State of the Union address in January, Haley shared the story of her parents immigrating to the United States from India and how her state has confronted racial division. Although she did not mention Trump during that speech, Haley later said that her message was directed at him.

"During anxious times, it can be tempting to follow the siren call of the angriest voices. We must resist that temptation," Haley said during her rebuttal. "No one who is willing to work hard, abide by our laws, and love our traditions should ever feel unwelcome in this country."