President Donald Trump warned would-be illegal immigrants advancing toward the U.S.-Mexico border that if they threw rocks at U.S. law enforcement or military it would be considered the same as firing on them, in a Thursday afternoon speech.

“Anybody throwing stones, rocks, like they did to Mexico and the Mexican military, Mexican police, where they badly hurt police and soldiers of Mexico, we will consider that a firearm,” Trump said, noting that some migrants have been violent while attempting to cross the Mexican-Guatemalan border.

These migrants threw rocks at members of Mexican law enforcement, injuring some of their authorities in an attempt to continue through towards the U.S. to claim asylum. The president has been incensed by the advancing caravan which has swelled to nearly 6,000 people, largely citizens of Central America.

The Trump administration is concerned because current U.S. law requires a lengthy asylum adjudication process and believes many migrants are using loopholes in U.S. law to illegally immigrate. Trump announced that he will issue an executive order to force asylum seekers to only enter at legal ports of entry, allowing for orderly processing.

Trump continued of any rock throwing “we will consider it, the maximum that we can consider that…We’re not going to put up with that. They want to throw rocks at our military, our military fights back….I told them to consider it a rifle.”