Donald Trump would consider asking lawmakers on Capitol Hill to pass a declaration of war against the Islamic State if he’s elected president, the presumptive Republican nominee said Monday.

“This is a war against people who are vicious, violent people that we have no idea who they are, where they come from. We are allowing tens of thousands of them into our country now so on top of wars on foreign land wait ’til you see what happens in the future,” Trump told Fox News’ Bill O’Reilly.