Kor said the hug wasn't planned, according to The Times.
“This shows that former enemies can get along as human beings," Kor said, according to The Times. "What on Earth do we want to tell the world? Killing each other has never created anything good. I want to teach young people that even former Nazis and survivors can get along.”
On Kor's blog, she described what it was like when Gröning kissed her on the cheek: "Well I probably wouldn't have gone that far, but I guess it is better than what he would have done to me 70 years ago."
Gröning, who said he kept watch as thousands of Jews were led to gas chambers, is charged with 300,000 counts of accessory to murder, The Associated Press reported.
Kor testified Wednesday, recalling the medical experiments she endured while at Auschwitz, The Times said. It was not immediately clear when the hug occurred.
Kor's blog post concluded, "My idea is for people from the victims' side and people from the perpetrators' side to come together, face the truth, try to heal, and work together to prevent it from ever happening again."
The Associated Press contributed to this report.