The outspoken billionaire made the remark during a televised debate late Thursday when asked about the student-led protests and subsequent government crackdown.
Specifically, CNN moderator Jake Tapper wanted Trump's response to critics who had expressed concern about previous Tiananmen comments Trump reportedly made to Playboy magazine in 1990.
"About China's massacre of pro-democracy protesters at Tiananmen Square, you've said: 'When the students poured into Tiananmen Square, the Chinese government almost blew it, then they were vicious, they were horrible, but they put it down with strength. That shows you the power of strength.' How do you respond?" Tapper asked.
"I was not endorsing it. I said that is a strong, powerful government that put it down with strength," he said.
"And then they kept down the riot. It was a horrible thing. It doesn't mean at all I was endorsing it."
Hundreds -- by some estimates more than a thousand -- died after the Communist Party sent tanks in June 1989 to crush demonstrations on Tiananmen Square in the Chinese capital, where student-led protesters had staged a peaceful sit-in to demand democratic reforms.