My amateur, non military take on what the President's words mean is the Pentagon has briefed the President on a series of options. The details of those plans include how specific weapons counter specific Iranian threats. For example the Mk 110 57mm naval gun is used by the USN with countering small boat swarms in mind. That's just one, there are others.
If necessary the military has some extremely unpleasant options that do not involve nuclear weapons. During the first Gulf War, Gen. Colin Powell was asked what would happen if Iraq used chemical weapons on U.S. troops. He casually responded that the Air Force could take out a dozen dams and flood Bagdad under eight feet of water. Iran has similar vulnerabilities.
If the news would analyze instead of criticize they might figure this out.
That was damn good for an amateur non-military take on things.
While flying they can hardly be seen. They have independent brains, but can be programed to fly in formations, seek out masses of people, seek single people, or separate into about a hundred each to hit buildings by using AI. When you push the button, they fly independently of the pilot but can be programed for a particular scenario. They don't miss. They can chase you down at about 100mph.