President Barack Obama said Monday that the man who killed dozens at an Orlando gay nightclub was “an example of homegrown extremism.”

Described as the deadliest mass shooting on American soil, 49 people died and 53 were injured when Omar S. Mateen, 29, opened fire at the Pulse nightclub.

Speaking from his Oval Office, Obama said that Mateen “was inspired by various extremist information that was disseminated over the Internet.”

“We see no clear evidence that he was directed externally. It does appear that at the last minute he announced allegiance to ISIL. … As far as we can tell right now, this is certainly an example of the kind of homegrown extremism that all of us have been so concerned about for a very long time.”

“Countering this extremist ideology is increasing going to be just as important as making sure that we are disrupting more extensive plots engineered from the outside,” he added.

Obama is scheduled to visit Orlando on Thursday.