"So sad, Sutherland Springs, Texas, such a beautiful, wonderful area with incredible people. Who would ever think a thing like this could happen," Trump said during a Tokyo press conference with Japanese Prime Minister Shinzo Abe.
"I think that mental health is your problem here. This was a very, based on preliminary reports, very deranged individual."
"But this isn't a guns situation. I mean, we could go into it, but it's a little bit soon to go into it," Trump added.
"[T]his is a mental health problem at the highest level," he said. "It's a very, very sad event."
At least 26 people were killed and another 20 injured when the suspected shooter, 26-year-old Devin Patrick Kelley, opened fire at the small town church located 30 miles southeast of San Antonio, Texas.
Over the weekend, Trump traveled to Asia as part of a five-nation tour.