Air carrier First Officer reported experiencing GPS jamming and while approaching near the IVETA fix; the aircraft made an unexpected turn to the right.

Narrative

In route to Kuwait from ZZZ; we experienced GPS jamming. Standard operating procedures were followed; and checklists completed for the associated EICAS messages. Getting closer to Kuwait we noticed thunderstorm activity on our route of flight. We opted to begin descent later to avoid them; as well as requesting and being cleared for 15 track miles left of course. After passing the weather we were given a descent; and clearance to proceed direct to KFR. We then were given additional vectors; then direct IVETA and clearance for the ILS Y 15R. Approaching IVETA with roll mode in LNAV; the aircraft did an unexpected turn to the right prior to IVETA. The Captain; PF; selected heading mode and manually controlled the heading of the aircraft. At that time; our ANP value was fluctuating well above the RNP value. I; PM; told ATC we had degraded GPS accuracy. We were then given vectors to intercept the final approach course for ILS 15R and proceeded as expected. Our ANP value was above RNP all the way to the parking stand; and our map showed the airplane in the incorrect location. Cause: GPS spoofing.