I'm writing a sci-fi novel set on Earth in the recent past. In the novel, an alien giant robot destroys numerous cities in North America.
The first such occurrence, New York City, receives a lot of attention in the text. It hasn't happened before, people are surprised, lots of people are killed, the military tries unsuccessfully to counterattack, and so on.
The next occurrence, Boston, receives less attention. The giant robot now has a name (Jormungandr), and its arrival is anticipated hours in advance, allowing most of the inhabitants to be evacuated. The military doesn't have the time to set up an ambush yet.
A number of other cities in North America are also destroyed before US government agencies predict that the next target will be Miami far enough in advance to prepare a trap for Jormungandr (that doesn't work).
After that, yet more cities are destroyed, before the US government works out a way to defeat Jormungandr as it attempts to cross the Pacific to Japan.
My problem is that Jormungandr is destroying city after city in much the same way, without the governments in charge of those cities being able to do anything about it. People are being evacuated, so it's really only property that's being destroyed. I'm not taking much text to describe all of this because I don't want these necessary but repetitive events to become tedious, but I also feel that the destruction of a whole city should somehow not become so trivial. I can't just not mention the destroyed cities either, since which cities are destroyed form a significant clue as to Jormungandr's future actions.
How can I balance the necessity of repeated major events in my story without trivializing them or making them seem tedious?