Check the specs in the paperwork or a plate on the TV itself. If designed solely for European use it may be 230 volts 50 Hz only. If it's merely a matter of the plug itself being a European type you can buy an adapter (Radio Shack ?) or if you feel confident enough strip the plug and buy a new US style one.
Of course there are other considerations -- a European TV may use the PAL system which is different from the US system -- talk to LG (see their website for helpline or e-mail address) who will no doubt know more about their TVs than I do.