He was careful not to allow them to declare him king, because the tribes were not yet united and it would have resulted in his immediate execution; Romans were not eager to have any break-away parts of the kingdom mounting revolution. His warnings to them that he would be killed were undoubtedly that: warnings. “Shut up, you are going to get me killed.” All this tells me is that he knew darn well that uniting factions to mount a revolution is dangerous business.
No, he told the disciples He would die. When Peter took exception to that (like you Peter was expecting a worldly kingdom) Jesus recognized Satan's ideas working through Peter.
Jesus' kingdom is far superior to any on earth. The real kingdom is a perfect one...not of this world.