I work in industrial manufacturing and I am going to be spending a couple of weeks in north east US visiting some trade shows, some potential clients and a couple of suppliers.
As packing space is, of course, very limited, I would appreciate any guidance on whether I need to take a suit (which would be normal here in Europe) or whether a good sports jacket with tie, dress shirt and slacks would be suitably professional?
Thanks for your thoughts,
Matt

It depends...
What do your colleagues wear out there? What do your clients wear? The NE is (generalizing) more formal than (for example) Florida - depending where you are and on what time of year.
There's a cast on packing. Packing a suit is as easy as packing a coat and pants.