President Donald Trump on Monday responded for the first time to the attack against a crowd of pro-Israel demonstrators in Boulder, Colorado.

"Yesterday's horrific attack in Boulder, Colorado, WILL NOT BE TOLERATED in the United States of America," Trump wrote on his conservative social media platform.

"Acts of Terrorism will be prosecuted to the fullest extent of the Law. This is yet another example of why we must keep our Borders SECURE, and deport Illegal, Anti-American Radicals from our Homeland. My heart goes out to the victims of this terrible tragedy, and the Great People of Boulder, Colorado!" the president added.

Eight people were injured on Sunday in what the FBI is calling an "act of terror."

The suspect, Mohamed Sabry Soliman, was allegedly heard yelling "Free Palestine" while throwing a "makeshift flamethrower" at a demonstration to raise awareness about the remaining hostages in Gaza, according to authorities.

The Department of Homeland Security on Monday said Soliman is in the U.S. illegally as his B2 visa expired in February 2023. Soliman had also applied for asylum in 2022.

While Trump seized on the fact that the alleged attacker was in the country illegally, Trump did not mention antisemitism in his statement.

While the administration said Trump was briefed on Sunday, his first public comments came nearly 24 hours after the attack.

This is a developing story. Please check back for updates.