Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action; Flight Crew Requested ATC Assistance / Clarification
Procedure; Airspace Structure
After departure; we were cleared to climb and maintain FL170.  ATC control notified us there was military activity observed in the airspace [ahead].We contacted [the airspace's] Defense Radar on frequency 12 minutes before entering; and were given permission to enter at the ZZZZZ waypoint. Departure airport ATC advised us to contact [The next country`s] control on frequency. We established contact with Control prior to entering [the] FIR (Flight Information Region) at ZZZZZ. Control told us to report ZZZZZ.The Captain was still in contact with Departure Control with the left radio prior to ZZZZZ with the First Officer talking to [next ATC] on the right Radio. Just prior to ZZZZZ; Departure Control notified us of traffic 12 o'clock. We noticed the traffic on our TCAS more than 20 mile and 100 feet below our altitude.At ZZZZZ; several attempts were made to contact Control.  We could hear ATC; however ATC would not respond to us.The Traffic on TCAS turned to TA followed by a RA to Climb.  We then noticed the fighter Jet turning right to pass off our left wing less than a mile. After the RA clear of conflict; we returned to FL170 and notified [the Departure ATC] we had an RA. We attempted to contact [next ATC] to notify them of the TCAS RA; they would not respond. We broadcasted in the blind three times of our TCAS RA. Again; we could hear them; but they would not respond to us.The intercept Jet Fighter circled behind us in an aggressive manner triggering another TCAS RA to climb. We again called ATC and notified them of a TCAS RA. They responded by telling us to return to FL170. We requested climb to FL300 but was denied; they told us to maintain FL170. The Jet Fighter took position behind and to the left of us (strike position). This continued for more than 10 minutes. After several requests to climb; we were finally given a climb clearance to FL300. The Jet fighter stayed with us until we climbed. No further incident followed. Both TCAS RA resulted in a 300-feet Climb deviation; followed by a return to assigned FL170.
[Report narrative contained no additional information.]
B747 flight crew reported that ATC advised them of military activity ahead. The flight crew got a TCAS RA after a fighter jet intercepted them.