As of now there's two LTE models.
"AT&T" version which has LTE bands 4 (AWS) and 17 (700 lower blocks B/C)
"Verizon" version which has LTE band 13 (700 upper block C) + CDMA/EVDO fall back.
I think in europe LTE is/will be used on 800 and 2600 bands, so definitely not compatibility at this time.